Add RELEASE comments for release checklist

Author: gilch

docs/command_line_reference.rst

@@ -14,6 +14,8 @@ also install the ``lissp`` command-line tool for running Lissp code.
 This is a convenience executable for starting ``python -m hissp``,
 whose minimal options were modeled after Python's most commonly used:
 
+.. RELEASE: Update (Hissp X.X.X) line.
+
 .. code-block:: Text
 
    usage: lissp [-h] [-i] [-c cmd] [file] [args [args ...]]

docs/lissp_whirlwind_tour.rst

@@ -9,6 +9,7 @@
    ...                 __import__('hissp')._macro_)))
 
 .. TODO: Interactive via web repl?
+.. RELEASE: Update the ;;;; Installation section.
 
 Lissp Whirlwind Tour
 ====================

docs/primer.rst

@@ -55,6 +55,8 @@ Confirm your Python version with
 
 (Re-)install the Hissp version matching this document with
 
+.. RELEASE: Rewrite to install from PyPI.
+
 .. code-block:: console
 
    $ python -m pip install --upgrade --force-reinstall git+https://github.com/gilch/hissp

src/hissp/__init__.py

@@ -88,7 +88,7 @@
 with __import__("contextlib").suppress(ImportError):
     from hissp.macros import _macro_
 
-VERSION = "0.5.dev"
+VERSION = "0.5.dev"  # RELEASE
 
 
 def prelude(env):