feat(#1974): experimental.git.async see https://github.com/nvim-tree/nvim-tree.lua/issues/2104 (#2094)

* async git watcher reload; callback hell for now

* async git watcher reload; revert unnecessary extractions

* async git watcher reload; callback and non-callback functions are required for sync codepaths that loop

* async git watcher reload

* async git watcher reload

* feat(#1974): experimental.git.async

* feat(#1974): experimental.git.async

doc/nvim-tree-lua.txt

@@ -438,6 +438,11 @@ applying configuration.
           trash = true,
         },
       },
+      experimental = {
+        git = {
+          async = false,
+        },
+      },
       log = {
         enable = false,
         truncate = false,
@@ -1224,6 +1229,16 @@ General UI configuration.
         Prompt before trashing.
           Type: `boolean`, Default: `true`
 
+*nvim-tree.experimental*
+Experimental features that may become default or optional functionality.
+
+    *nvim-tree.experimental.git.async*
+    Direct file writes and `.git/` writes are executed asynchronously: the
+    git process runs in the background. The tree updates on completion.
+    Other git actions such as first tree draw and explicit refreshes are still
+    done in the foreground.
+      Type: `boolean`, Default: `false`
+
 *nvim-tree.log*
 Configuration for diagnostic logging.