document performance issues and add to bug report template (#1111)

README.md

@@ -334,10 +334,37 @@ You can toggle the help UI by pressing `g?`.
 
 ## Diagnostic Logging
 
-You may enable diagnostic logging and a file `nvim-tree-HH:MM:SS-username.log` will be created in `$XDG_CACHE_HOME/nvim`, usually `~/.cache/nvim`, containing logs from that nvim session. See `:help nvim-tree.log`.
+You may enable diagnostic logging and a file `nvim-tree.log` will be created in `$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.
 
+## Performance Issues
+
+If you are experiencing performance issues with nvim-tree.lua, you can enable profiling in the logs. It is advisable to enable git logging at the same time, as that can be a source of performance problems.
+
+```lua
+log = {
+  enable = true,
+  truncate = true,
+  types = {
+    git = true,
+    profile = true,
+  },
+},
+```
+
+Please attach `$XDG_CACHE_HOME/nvim/nvim-tree.log` if you raise an issue.
+
+*Performance Tips:*
+
+* If you are using fish as an editor shell (which might be fixed in the future), try set `shell=/bin/bash` in your vim config.
+
+* Try manually running the git command (see the logs) in your shell e.g. `git --no-optional-locks status --porcelain=v1 --ignored=matching -u`.
+
+* Huge git repositories may timeout after the default `git.timeout` of 400ms. Try increasing that in your setup if you see `[git] job timed out` in the logs.
+
+* Try temporarily disabling git integration by setting `git.enable = false` in your setup.
+
 ## Screenshots
 
 ![alt text](.github/screenshot.png?raw=true "kyazdani42 tree")