This was changed in simplepie#745
but without any rationale. The only HTML file is in tests and that should not be manually edited at all.

Ran the following within `nix-shell -I 'nixpkgs=channel:nixos-unstable' -p zola`
to create the website tree:

    zola init docs

Filled in the website URL and disabled everything for now.

Then created templates based on the successive commits.

There are only two markdown files and both use 2 spaces.

Ran the following within `nix-shell -I 'nixpkgs=channel:nixos-unstable' -p wget2 yq-go dos2unix 'python3.withPackages (ps: with ps; [ beautifulsoup4 pypandoc ])' nodePackages.prettier`

```sh
# Download the website contents from the web, and the pages that fail with error 500 from Internet Archive.
wget2 --user-agent 'Mozilla/5.0 (X11; Linux x86_64; rv:106.0) Gecko/20100101 Firefox/106.0' --mirror --force-directories --no-robots --retry-on-http-error=403 --http2-request-window=1 --random-wait --exclude-directories=/wiki/lib/exe/ http://simplepie.org
rm simplepie.org/blog/2006/03/06/forums-powered-by-punbb/index.html
wget2 https://web.archive.org/web/20190404091911/simplepie.org/blog/2006/03/06/forums-powered-by-punbb/ --directory-prefix=simplepie.org/blog/2006/03/06/forums-powered-by-punbb
rm simplepie.org/blog/2012/10/30/simplepie-1-3-1-is-now-available/index.html
sed -i 's/\xbb//' docs/content/blog/2006-03-06-forums-powered-by-punbb.html # fix encoding
wget2 https://web.archive.org/web/20210812123158/https://simplepie.org/blog/2012/10/30/simplepie-1-3-1-is-now-available/ --directory-prefix=simplepie.org/blog/2012/10/30/simplepie-1-3-1-is-now-available

# Copy the downloaded contents into the website tree.
cp -r simplepie.org/* docs/content
mkdir -p docs/static
mv docs/content/{scripts,favicon.ico,images,css,robots.txt} docs/static

# Standardize line endings.
dos2unix docs/**

# Drop API docs, we will generate them later.
rm -r docs/content/api

# Drop mint (analytics), it is abandoned.
rm -r docs/content/mint

# Drop dynamically generated demo pages.
rm -r docs/content/demo/newsblocks

# Drop downloads – we will just link GitHub.
rm docs/content/downloads/*\?* docs/content/downloads/*.zip

# Drop ancient scripts, no more font replacement using flash, or tricks to make PNGs transparent in IE (Sleight).
rm -r docs/static/css/sIFR-* docs/static/scripts/

# Download headers explicitly since they are currently rotated by PHP
# and wget was not able to find them.
rm docs/static/images/headers/rotate-old.php
wget http://simplepie.org/images/headers/rotate-xspf.xml --directory-prefix docs/static/images/headers/
cat docs/static/images/headers/rotate-xspf.xml | yq -p=xml '"http://simplepie.org" + .playlist.trackList.track[].location' | xargs wget --directory-prefix docs/static/images/headers/

# Drop Wordpress plug-in clutter.
rm -r docs/content/blog/wp-{content,includes,json}

# Drop feeds.
rm docs/content/blog/**/feed/index.html
rmdir docs/content/blog/**/feed

# Drop wiki noise.
rm docs/content/wiki/lib/exe/css.php?*
mv docs/content/wiki/lib/tpl/simplepie/wikistyles.css docs/static/css/
mv docs/content/wiki/lib/images/smileys/icon_exclaim.gif docs/static/images/
rm -r docs/content/wiki/lib
rm docs/content/wiki/feed.php*
rm -r docs/content/wiki/{_detail,_export}
find docs/content/wiki/ -name '*\?idx=*' -exec rm '{}' \;
find docs/content/wiki/ -name '*\?do=*' -exec rm '{}' \;
rm docs/content/wiki/_media/wiki/dokuwiki-128.png docs/content/wiki/wiki/dokuwiki
rmdir docs/content/wiki/wiki
mv 'docs/content/wiki/_media/tutorial/update_simplepie_cache.jpg?cache=' 'docs/content/wiki/_media/tutorial/update_simplepie_cache.jpg'
rm docs/content/wiki/_media/tutorial/update_simplepie_cache.jpg\?*

# Add extension to wiki pages.
find docs/content/wiki -type f ! -name '*.jpg' ! -name '*.html' -print0 | xargs -0 -I '{}' mv '{}' '{}.html'

# Remove duplicate wiki page
rm docs/content/wiki/faq/Supported_Character_Encodings.html
echo /wiki/faq/Supported_Character_Encodings /wiki/faq/supported_character_encodings >> docs/static/_redirects
rm docs/content/wiki/plugins/wordpress/simplepie_plugin_for_wordpress.1.html
# Rename start files (used as directory index in DokuWiki) to _index.html used by Zola.
find docs/content/wiki/ -name start.html | sed -E 's#(docs/content/(.*))/start.html#mv "\0" "\1/_index.html"; echo "/\2/start /\2/" >> docs/static/_redirects#g' | sh -

# Simplify blog structure.
rm -r docs/content/blog/page docs/content/blog/index.html
find docs/content/blog/2* -name index.html | sed -E 's#docs/content/blog/(....)/(..)/(..)/(.*)/index.html#mv "\0" "docs/content/blog/\1-\2-\3-\4.html"#g' | sh -
rmdir docs/content/blog/*/*/*/*
rmdir docs/content/blog/*/*/*
rmdir docs/content/blog/*/*
rmdir docs/content/blog/????
ls docs/content/blog/*.html | sed -E 's#docs/content/blog/(....)-(..)-(..)-(.+)\.html#/blog/\1/\2/\3/\4/ /blog/\4/#g' >> docs/static/_redirects

# Prepare redirects for Apache
sed -i 's/^/Redirect 302 /' docs/static/_redirects
mv docs/static/{_redirects,.htaccess}

# Manually extracted main template into templates/.
```

Produced by markdownify.py

They are big and many are outdated.

So that Zola does not complain about being broken once we remove the wiki.