- add a link to a second page for maintenance instructions

HOWTO.md

@@ -0,0 +1,17 @@
+# How to maintain the Zope versions page
+
+The [Zope version configuration page](./README.md) and the linked
+version and requirements files are built from a special branch of
+the [Zope GitHub repository](https://github.com/zopefoundation/Zope).
+
+```bash
+  $ git clone -b gh-pages git@github.com:zopefoundation/Zope
+  $ cd Zope
+  $ ./build_indexes
+  $ git add README.md releases/
+  $ git commit -m "Add new Zope releases."
+  $ git push origin gh-pages
+```
+
+The end result is available at https://zopefoundation.github.io/Zope/.
+

README.md

@@ -35,3 +35,7 @@
 * [versions-prod.cfg](releases/2.13.26/versions-prod.cfg)
 * [requirements.txt](releases/2.13.26/requirements.txt)
 
+
+_____
+
+[How to maintain this page](HOWTO.md)

build_index.sh

@@ -25,3 +25,7 @@ for tag in "2.13.26"; do
     git show $tag:requirements.txt > releases/$tag/requirements.txt && printf "* [requirements.txt](releases/$tag/requirements.txt)\n" >> README.md || rm releases/$tag/requirements.txt
     printf "\n" >> README.md
 done
+
+# Add a footer
+printf "\n_____\n\n" >> README.md
+printf "[How to maintain this page](HOWTO.md)\n" >> README.md