consolidated script documentation into a single md file

wrote documentation on terminal sound effects

added a sound effect for `invoke`

added the function `build-drv`, which is a wrapper for nix-build that
puts the output nix store path to the derivation into an environment
variable instead of symlinking it in the current working directory

docs/sounds.md

@@ -0,0 +1,42 @@
+# Terminal Sound Effects
+
+---
+
+My zsh configuration has several aliases and wrapper functions that essentially wrap commands such that they play a sound effect when
+invoked. The sound effects are from Earthbound, and are stored in `assets/sound`. Notable examples include `ls` and `cd` which
+both play a sound when invoked, among some of the other common utilities, for both GNU and NixOS. If you wish to disable these sound
+effects, you can do so by changing the `SOUNDS_ENABLED` environment variable defined in `modules/home/environment/zsh/env.nix` from `true` to `false`.
+
+---
+
+The aliases and commands which use sound effects are:
+
+- `grimblast`
+	- Uses: `assets/sound/screenshot.wav`
+
+- `ls`
+	- Uses: `assets/sound/ls.wav`
+
+- `cd`
+	- Uses: `assets/sound/cd.wav`
+
+- `gcomm (alias for 'git commit')`
+	- Uses: `assets/sound/gitcommit.wav`
+
+- `gpush (alias for 'git push')`
+	- Uses: `assets/sound/`
+
+- `gpull (alias for 'git pull')`
+	- Uses: `assets/sound/gitpull.wav`
+
+- `greb (alias for 'git rebase')`
+	- Uses: `assets/sound/gitrebase.wav`
+
+- `ga (alias for 'git add')`
+	- Uses: `assets/sound/gitadd.wav`
+
+- `gtp (alias for 'gtrash put')`
+	- Uses:  `assets/sound/rm.wav`
+
+- `rebuild`
+	- Uses: `assets/sound/update.wav` or `assets/sound/error.wav`