Added modifiers head and tail (cursorless-dev#39)

src/modifiers/head_tail.py

@@ -0,0 +1,8 @@
+from talon import Module
+
+mod = Module()
+
+
+@mod.capture(rule="head | tail")
+def cursorless_head_tail(m) -> str:
+    return {"modifier": {"type": m[0]}}

src/primitive_target.py

@@ -23,7 +23,8 @@
     "<user.cursorless_position>",  # before, above, end of
     "<user.cursorless_selection_type>",  # token, line, file
     "<user.cursorless_containing_scope>",  # funk, state, class
-    "<user.cursorless_subtoken>"  # first past second word
+    "<user.cursorless_subtoken>",  # first past second word
+    "<user.cursorless_head_tail>" # head, tail
     # "<user.cursorless_inside_outside>",       # inner, outer
     # "<user.cursorless_surrounding_pair>",     # curly, round
     # "<user.cursorless_matching_pair_symbol>", # matching