docs: add install.sh, Dependencies/Requirements sections

Add install.sh: system install as root, user install (~/.local, XDG)
as normal user, with a PATH warning and an uninstall subcommand. It
detects the bash-completion dir (underscore vs hyphen). Expand the
README Dependencies section (required vs optional) and point
Installation at the script; add a REQUIREMENTS section to the man page.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

4 files changed, 115 insertions, 11 deletions

diff --git a/README.md b/README.md
index 895b94c..a9f6ad9 100644
--- a/README.md
+++ b/README.md
@@ -6,21 +6,27 @@ Manage hint files for slackrepo scripts. Updates version strings and download ch
 
 ## Installation
 
-### Script
+The `install.sh` script installs the binary, bash completion, and man page. Run
+it as root for a system-wide install, or as a normal user for a user-only
+install under `~/.local`:
 
 ```bash
-sudo cp mkhint /usr/local/bin/mkhint
+./install.sh              # system-wide (as root) or user-only (as normal user)
+./install.sh uninstall    # remove the installed files
 ```
 
-### Bash Completion
+System paths: `/usr/local/bin/mkhint`, `/usr/local/man/man1/mkhint.1.gz`, and
+the bash completion in whichever of `/etc/bash_completion.d` or
+`/etc/bash-completion.d` exists (defaulting to the underscore form on
+Slackware). User paths follow XDG: `~/.local/bin`, `~/.local/share/man/man1`,
+and `~/.local/share/bash-completion/completions`. On Slackware `~/.local/bin` is
+not on `PATH` by default; the script warns when the install dir is unreachable.
 
-```bash
-sudo cp mkhint.bash-completion /etc/bash-completion.d/mkhint
-```
-
-### Man Page
+To install by hand instead:
 
 ```bash
+sudo cp mkhint /usr/local/bin/mkhint
+sudo cp mkhint.bash-completion /etc/bash_completion.d/mkhint
 sudo cp mkhint.1.gz /usr/local/man/man1/mkhint.1.gz
 ```
 
@@ -35,9 +41,21 @@ pandoc mkhint.1.md -s -t man -o mkhint.1 && gzip -9 -n -f mkhint.1
 
 ### Dependencies
 
-- `wget` — for downloading archives and calculating checksums
-- `nvchecker` — for checking upstream versions (provides `nvchecker` and `nvtake`)
-- `jq` — for parsing version check results
+**Required:**
+
+- `slackrepo` — the tool whose hint files `mkhint` manages; dispatched after a version bump
+- `wget` — downloading archives and calculating checksums
+- `nvchecker` — checking upstream versions (provides both `nvchecker` and `nvtake`)
+- `jq` — parsing version-check results and GitHub API responses (bundled-dep reconcile)
+
+**Optional (features degrade gracefully if absent):**
+
+- `git` — side-by-side diffs in `--review`, `--list <pkg>`, and `--info`; falls back to `diff -y`
+- `less` — paging the README in `--info` when it is taller than the terminal
+- `tput` — TTY color detection; output is plain without it
+
+`perl`, `awk`, `sed`, `grep`, `md5sum`, and other coreutils are part of a base
+Slackware install and are assumed present.
 
 ### Configuration
 
diff --git a/install.sh b/install.sh
new file mode 100755
index 0000000..0cb916d
--- /dev/null
+++ b/install.sh
@@ -0,0 +1,78 @@
+#!/bin/bash
+# install.sh — install (or uninstall) mkhint, its bash completion, and man page.
+#
+# Run as root for a system-wide install, or as a normal user for a user-only
+# install under ~/.local. Usage:
+#
+#   ./install.sh              system install if root, else user install
+#   ./install.sh uninstall    remove the files from wherever they were installed
+#
+# Copyright (C) 2026 Danilo M. <danix@danix.xyz>
+# Licensed under the GNU GPL v2 (see LICENSE).
+
+set -e
+
+SRC_DIR="$(cd "$(dirname "$0")" && pwd)"
+
+BIN_SRC="$SRC_DIR/mkhint"
+COMP_SRC="$SRC_DIR/mkhint.bash-completion"
+MAN_SRC="$SRC_DIR/mkhint.1.gz"
+
+# Pick paths based on privilege.
+if [[ $EUID -eq 0 ]]; then
+    MODE="system"
+    BIN_DIR="/usr/local/bin"
+    MAN_DIR="/usr/local/man/man1"
+    # Slackware ships /etc/bash_completion.d (underscore); some distros use the
+    # hyphen. Install to whichever exists, defaulting to underscore.
+    if [[ -d /etc/bash-completion.d ]]; then
+        COMP_DIR="/etc/bash-completion.d"
+    else
+        COMP_DIR="/etc/bash_completion.d"
+    fi
+else
+    MODE="user"
+    BIN_DIR="$HOME/.local/bin"
+    MAN_DIR="$HOME/.local/share/man/man1"
+    COMP_DIR="$HOME/.local/share/bash-completion/completions"
+fi
+
+BIN_DST="$BIN_DIR/mkhint"
+COMP_DST="$COMP_DIR/mkhint"
+MAN_DST="$MAN_DIR/mkhint.1.gz"
+
+if [[ "$1" == "uninstall" ]]; then
+    echo "Uninstalling mkhint ($MODE)..."
+    rm -fv "$BIN_DST" "$COMP_DST" "$MAN_DST"
+    echo "Done."
+    exit 0
+fi
+
+if [[ -n "$1" ]]; then
+    echo "Unknown argument: $1" >&2
+    echo "Usage: $0 [uninstall]" >&2
+    exit 1
+fi
+
+# Sanity-check sources before touching the filesystem.
+for f in "$BIN_SRC" "$COMP_SRC" "$MAN_SRC"; do
+    if [[ ! -f "$f" ]]; then
+        echo "Missing source file: $f" >&2
+        exit 2
+    fi
+done
+
+echo "Installing mkhint ($MODE)..."
+install -Dm755 "$BIN_SRC"  "$BIN_DST"  && echo "  $BIN_DST"
+install -Dm644 "$COMP_SRC" "$COMP_DST" && echo "  $COMP_DST"
+install -Dm644 "$MAN_SRC"  "$MAN_DST"  && echo "  $MAN_DST"
+echo "Done."
+
+# On Slackware ~/.local/bin is not on PATH by default; warn if the bin dir is
+# not reachable so the user knows to fix it.
+case ":$PATH:" in
+    *":$BIN_DIR:"*) ;;
+    *) echo
+       echo "NOTE: $BIN_DIR is not on your PATH."
+       echo "      Add it, e.g.:  export PATH=\"$BIN_DIR:\$PATH\"" ;;
+esac
diff --git a/mkhint.1.gz b/mkhint.1.gz
index 9ca085c..75c4e10 100644
--- a/mkhint.1.gz
+++ b/mkhint.1.gz
diff --git a/mkhint.1.md b/mkhint.1.md
index 28f294b..a3bffe2 100644
--- a/mkhint.1.md
+++ b/mkhint.1.md
@@ -41,6 +41,14 @@ After a version-changing update, **mkhint** dispatches **slackrepo** for the
 affected package: `slackrepo update` if the package is already built in the
 package repository, `slackrepo build` if it is not.
 
+# REQUIREMENTS
+
+Required: **slackrepo**, **wget**, **nvchecker** (which also provides
+**nvtake**), and **jq**. Optional: **git** (nicer side-by-side diffs, falls back
+to `diff -y`), **less** (paging in **\--info**), and **tput** (color on a TTY).
+Coreutils (**perl**, **awk**, **sed**, **grep**, **md5sum**) are assumed from a
+base Slackware install.
+
 # OPTIONS
 
 **\--set-version**, **-V** *VERSION*