Base: Add manpage for pkg

Author: https://github.com/cubiclove
Commit: 842b2a01e6
Pull-request: https://github.com/SerenityOS/serenity/pull/21014
Reviewed-by: https://github.com/supercomputer7 ✅

Base/usr/share/man/man1/pkg.md

@@ -0,0 +1,34 @@
+## Name
+
+pkg - Package Manager
+
+## Synopsis
+
+```**sh
+$ pkg [-l] [-d] [-u] [-v] [-q package]
+```
+
+## Description
+
+This program can list installed packages and query for [available packages](https://github.com/SerenityOS/serenity/blob/master/Ports/AvailablePorts.md). The [Ports for SerenityOS website](https://ports.serenityos.net) has more detailed information about available packages.
+
+It does not currently support installing and uninstalling packages. To install third-party software use the [Ports system](https://github.com/SerenityOS/serenity/blob/master/Ports/README.md).
+
+## Options
+
+* `-l`, `--list-manual-ports`: Show all manually-installed ports
+* `-d`, `--list-dependency-ports`: Show all dependencies' ports
+* `-u`, `--update-ports-database`: Sync/Update ports database
+* `-v`, `--verbose`: Verbose output
+* `-q`, `--query-package`: Query the ports database for package name
+
+## Arguments
+
+* `package`: The name of the package you want to query
+
+## Example
+
+```sh
+# Query the ports database for the serenity-theming package
+$ pkg -q serenity-theming
+```