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/virtual_environments/auto-venv/path_extensions.nu

@@ -0,0 +1,59 @@
+
+# Returns a list of full paths starting from root, to the path given
+# 
+# 
+# walk '/home/user/projects';
+# > [
+# >   '/home/',
+# >   '/home/user/',
+# >   '/home/user/projects/',
+# > ]
+# 
+export def "path walk" [
+    path: any
+] {
+    let list = ($path | path expand | path split);
+
+    $list | each -n { |$part| (
+        $list | first ($part.index + 1) | path join;
+    )}
+
+}
+
+# Returns true if 'subfolder' is found along the path of 'folder', with a given type
+export def "path check-sub" [
+    folder:    any, 
+    subfolder: string,
+    --type:    string
+] {
+
+    (ls -a $folder
+        | where ( 
+            ($type == $nothing or $it.type == $type)
+            and ($it.name | path basename) == $subfolder
+        )
+        | length 
+    ) > 0;
+}
+
+# Walks the path along 'folder', and returns the path of the first subfolder found, or nothing if the subfolder was not found.
+# 
+# path find-sub '/home/user/projects/code' '.venv';
+# > /home/user/projects/.venv
+export def "path find-sub" [
+    folder:    any,
+    subfolder: string,
+    --type:    string
+] {
+    let paths = path walk $folder;
+
+    let paths = ( $paths 
+        | where (
+            path check-sub $it $subfolder --type $type
+        )
+    );
+
+    if ($paths != $nothing) and ($paths | length) > 0 {
+        [ ($paths | first), $subfolder ] | path join
+    }
+}