refactor: ✨ (#418)

* refactor: ✨ move in one commit

Eveything in modules should probably be changed to `exported` defs.
The idea is to move everything first to keep proper history.

* refactor: 📝 add modules readme (wip)

* refactor: ✨ small move

* refactor: 📝 changed nestring, updated modules readme

* refactor: 📝 to document or not to document

* fix: 🐛 themes

replaced the template to use `main` and regenerated them
from lemnos themes.

* Revert "fix: 🐛 themes"

This reverts commit 4918d3633c8d2d81950a0ed0cfd9eb84241bc886.

* refactor: ✨ introduce sourced

- Created a source `root` in which sourcable demos are stored.
  Some might get converted to modules later on.
- Moved some files to bin too.

* fix: 🐛 fehbg.nu

* fix: 🐛 modules/after.nu

* moved some other stuff around

---------

Co-authored-by: Darren Schroeder <343840+fdncred@users.noreply.github.com>

modules/rbenv/rbenv.nu

@@ -0,0 +1,38 @@
+# rbenv
+export-env { 
+    load-env {
+        PATH: ($env.PATH | split row (char esep) | prepend [$"($env.HOME)/.rbenv/bin" $"($env.HOME)/.rbenv/shims"])
+        RBENV_VERSION: ""
+        RBENV_VERSION_OLD: ""
+        RBENV_SHELL: "nu"
+    }
+}
+
+export def-env rbenv [
+	command?: string@'nu-complete rbenv',
+	...args
+] {
+    let new_env = if $command in ["rehash", "shell"] {
+        # implement each on indiviudaly e.g.
+        if $command == "shell" {
+            { RBENV_VERSION_OLD: $env.RBENV_VERSION RBENV_VERSION: $args.0 }
+        } else {
+            error make { msg: $"`($command)` command is not supported yet" }
+        }
+    } else {
+    	if ($command | is-empty) {
+    		^rbenv
+    	} else {
+        	^rbenv $command $args
+    	}
+        {}
+    }
+    load-env $new_env
+}
+
+def 'nu-complete rbenv' [] {
+    ^rbenv help
+    | lines
+    | where ($it | str starts-with "   ")
+    | each {|entry| $entry | split row ' ' | get 0 }
+}