Base: Add man page for keymap(1)

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

@@ -0,0 +1,28 @@
+## Name
+
+keymap - load a keyboard layout
+
+## Synopsis
+
+```**sh
+# keymap <name|file>
+```
+
+## Description
+
+The `keymap` utility can be used to set a keyboard layout using the given name or file.
+
+Loading by name will search for keyboard layout files in `/res/keymaps/*.json`.
+
+## Examples
+
+Load a keyboard layout by name:
+```sh
+# keymap en
+```
+
+Load a keyboard layout using a file:
+```sh
+# keymap /res/keymaps/en.json
+# keymap ./map.json
+```