Make layout API-interface a bit simpler

Additionally, also fix a bug when creating a window, where as if the
session name was the same as a window that already existed, it would
fail, accidentally using the window rather than the session at a target.

templates/session.sh

@@ -1,14 +1,16 @@
-# Set custom session name. Default is based on filename.
-# session_name "Example Session"
+# Set a custom session root path. Default is `$HOME`.
+# Must be called before `initialize_session`.
+#session_root "~/Projects/example"
 
-# Set a custom session root. Default is `$HOME`.
-# session_root "~/Projects/example"
+# Create session with specified name if it does not already exist. If no
+# argument is given, session name will be based on layout file name.
+if initialize_session "{{SESSION_NAME}}"; then
 
-# Create session if it does not already exist.
-if initialize_session; then
+  # Create a new window inline within session layout definition.
+  #new_window "misc"
 
-  # Load window layouts if session was created.
-  # load_window "example"
+  # Load a defined window layout.
+  #load_window "example"
 
 fi
 

templates/window.sh

@@ -1,14 +1,13 @@
-# Set custom window name. Default is based on filename.
-# window_name "Example Window"
+# Set window root path. Default is `$session_root`.
+# Must be called before `new_window`.
+#window_root "~/Projects/example"
 
-# Set a window root path. Default is `$session_root`.
-# window_root "~/Projects/example"
-
-# Create new window. Remove if you want to apply layout to current window.
-tmux new-window -t "$session" -n "$window"
+# Create new window. If no argument is given, window name will be based on
+# layout file name.
+new_window "{{WINDOW_NAME}}"
 
 # Split window into panes.
-# tmux split-window -t "$session:$window.0" -h -p 20
+#tmux split-window -t "$session:$window.0" -h -p 20
 
 # Set active pane.
-# tmux select-pane -t "$session:$window.0"
+#tmux select-pane -t "$session:$window.0"