refactor(tmux:plugin): move loading plugins to tmux.conf

  ## what
  - move loading plugins to `tmux.conf`
    - move loading plugins from `./tools/tmux/plugins.tmux.conf` to `./tools/tmux/tmux.conf`

  ## how

  ## why
  -  since im using config from https://github.com/gpakosz/.tmux , it
     doesn't seem to load plugins if sourcing from another file
     - check gpakosz/.tmux#671

  ## where
  - ./tools/tmux/tmux.conf

  ## usage

tools/tmux/tmux.conf

@@ -26,7 +26,7 @@ set-option -ga terminal-overrides ",xterm-256color:Tc"
 # import settings from files
 
 source-file ~/dotfiles/tools/tmux/hotkeys.tmux.conf
-source-file ~/dotfiles/tools/tmux/plugins.tmux.conf
+# source-file ~/dotfiles/tools/tmux/plugins.tmux.conf
 source-file ~/dotfiles/tools/tmux/theme.tmux.conf
 
 ##################################################################################################
@@ -41,3 +41,25 @@ set-environment -g TMUX_PLUGIN_MANAGER_PATH "$TMUX_PLUGIN_CACHE_PATH"
 # # Initialize TMUX plugin manager (keep this line at the very bottom of tmux.conf)
 # run -b '$TMUX_PLUGIN_CACHE_PATH/tpm/tpm'
 
+#################################################################################################
+# loading plugins
+# this is to work with oh-my-tmux from https://github.com/gpakosz/.tmux
+#
+# doesn't seem to work if sourcing the file plugins.tmux.conf
+# check https://github.com/gpakosz/.tmux/issues/671
+
+# sensible tmux config
+set -g @plugin 'tmux-plugins/tmux-sensible'
+
+# copy text in tmux
+set -g @plugin 'tmux-plugins/tmux-yank'
+
+# mouse support
+set -g @plugin 'nhdaly/tmux-better-mouse-mode'
+
+# popup menu to help manage tmux
+# <prefix> + \    open popup
+# <prefix> + <    displays some windows handling options
+# <prefix> + >    displays some pane handling options
+set -g @plugin 'jaclu/tmux-menus'
+