Added support for -f flag to use non-default tmux config file

CHANGES

@@ -6,6 +6,13 @@
 
 #### What's new
 
+- #479: Support loading tmux server with config file by passing `-f`
+
+ Note: This matches the behavior of `tmux`'s `-f`, the configuration will only
+ once when the server is started. If you need to apply source to a server after
+ it is running then use `tmux source-file`.
+
+ Credit: @lins05, via #734
 - #672: Panes now accept `shell` for their initial command.
 
  Equivalent to `tmux split-windows`'s `[shell-command]`

tmuxp/cli.py

@@ -561,6 +561,8 @@ def load_workspace(
  ``tmux -S <socket-path>``
  new_session_name: str, options
  ``tmux new -s <new_session_name>``
+ tmux_config_file: str, optional
+ ``tmux -f <config-file>``
  colors : str, optional
  '-2'
  Force tmux to support 256 colors