File logging (#1053)

* add file logging infrastructure

* log git runner operations

* log configuration and mappings

* document file logging infrastructure

* style fixes

* stylua fixes

* document log file locations

README.md

@@ -186,7 +186,15 @@ require'nvim-tree'.setup {
         }
       }
     }
-  }
+  },
+  log = {
+    enable = false,
+    types = {
+      all = false,
+      config = false,
+      git = false,
+    },
+  },
 }
 ```
 
@@ -307,6 +315,11 @@ You can toggle the help UI by pressing `g?`.
 3. `toggle` has a second parameter which allows to toggle without focusing the explorer (`require"nvim-tree.toggle(false, false)`).
 4. You can allow nvim-tree to behave like vinegar (see `:help nvim-tree-vinegar`).
 
+## Diagnostic Logging
+
+You may enable diagnostic logging and a file `nvim-tree-HH:MM:SS-username.log` will be created in `$XDG_CACHE_HOME/nvim`, usually `~/.cache/nvim`, containing logs from that nvim session. See `:help nvim-tree.log`.
+
+The files may become large and numerous, so it is advised to turn on logging to diagnose an issue or while reporting a bug, then turn it off.
 
 ## Screenshots