Document the ! (not) and . (source) aliases more

doc_src/cmds/not.rst

@@ -9,6 +9,7 @@ Synopsis
 .. synopsis::
 
     not COMMAND [OPTIONS ...]
+    ! COMMAND [OPTIONS ...]
 
 
 Description
@@ -16,6 +17,8 @@ Description
 
 ``not`` negates the exit status of another command. If the exit status is zero, ``not`` returns 1. Otherwise, ``not`` returns 0.
 
+Some other shells only support the ``!`` alias.
+
 The **-h** or **--help** option displays help about using this command.
 
 Example

doc_src/cmds/source.rst

@@ -10,6 +10,7 @@ Synopsis
 
     source FILE [ARGUMENTS ...]
     SOMECOMMAND | source
+    . FILE [ARGUMENTS ...]
 
 
 Description
@@ -23,7 +24,8 @@ If no file is specified and stdin is not the terminal, or if the file name ``-``
 
 The exit status of ``source`` is the exit status of the last job to execute. If something goes wrong while opening or reading the file, ``source`` exits with a non-zero status.
 
-**.** (a single period) is an alias for the ``source`` command. The use of **.** is deprecated in favour of ``source``, and **.** will be removed in a future version of fish.
+Some other shells only support the **.** alias (a single period).
+The use of **.** is deprecated in favour of ``source``, and **.** will be removed in a future version of fish.
 
 ``source`` creates a new :ref:`local scope<variables-scope>`; ``set --local`` within a sourced block will not affect variables in the enclosing scope.
 

doc_src/fish_synopsis.py

@@ -53,7 +53,7 @@ lexer_rules = [
         # Hack: treat the "[ expr ]" alias of builtin test as command token (not as grammar
         # metacharacter).  This works because we write it without spaces in the grammar (like
         # "[OPTIONS]").
-        (r"\[ | \]", Name.Constant),
+        (r"\. |! |\[ | \]", Name.Constant),
         # Statement separators.
         (r"\n", Text.Whitespace),
         (r";", Punctuation),