feat: add yadm completions to the repo (#960)

This is a request to add yadm completions to the repo.
These resemble the ones that are written for. The git one in your repo.
Yadm is a dotfiles manager that leverages `git` but uses your home
directory by default.

To see the tool go to <https://yadm.io/docs/overview>

modules/yadm/README.md

@@ -0,0 +1,25 @@
+# Yadm
+
+Yadm is a dot files manager that is written in Bash.
+The code in this module reflects this fact.
+The functions in this repo are typed wrappers around yadm.
+
+## Usage
+
+To use this module make sure you have installed yadm.
+
+Then copy this folder to the folder where you place your nu scripts
+Which is usually in `$"($nu.default-config-dir)"/scripts`.
+
+Then reference the folder by doing in the scripts/mod.nu file.
+
+```nu
+ export module yadm
+```
+
+## Contributing
+
+This module doesn't represent all of git's functionality.
+Which means it doesn't allow you to do everything git can.
+if there is something missing please submit a PR to this repo.
+If you can help please checkout git completions for a reference.