about: Remove outdated About pages and rewrite About

These pages are trying to convince the reader that Git is better than
Subversion, which isn't the relevant thing to communicate to people
learning about Git today.

Write a single short About page, and make the rest of the About pages
redirect to /about

Also:
- remove special "About" template
- remove tests for "small-and-fast"

Signed-off-by: Julia Evans <julia@jvns.ca>

Author: jvns

content/about/_index.html

@@ -1,6 +1,80 @@
 ---
-redirect_to: about/branching-and-merging
 url: /about.html
+section: "about"
 aliases:
 - /about/index.html
+- /about/branching-and-merging.html
+- /about/branching-and-merging/index.html
+- /about/data-assurance.html
+- /about/data-assurance/index.html
+- /about/distributed.html
+- /about/distributed/index.html
+- /about/free-and-open-source.html
+- /about/free-and-open-source/index.html
+- /about/small-and-fast.html
+- /about/small-and-fast/index.html
+- /about/staging-area.html
+- /about/staging-area/index.html
 ---
+
+<div id="main">
+<h1> About Git </h1>
+
+<h2> Git is fast </h2>
+
+<p>
+Git was built to work on the Linux kernel, meaning that it was built to handle
+repositories with tens of millions of lines of code from the start.
+Speed and performance has always been a primary design goal of Git.
+</p>
+
+<p>
+Git also stores repository history efficiently. As of 2025, the current version
+of the Linux kernel's source code is 1.7 GB.
+Git stores the full history of the Linux project (1.4 million commits) in only 5.5 GB.
+</p>
+
+<h2> Git is widely used </h2>
+
+<p>
+According to the <a href="https://survey.stackoverflow.co/2022/#version-control-version-control-system-prof">2022 Stack Overflow developer survey</a>,
+96% of professional developers use Git.
+</p>
+
+<h2> Git has a huge ecosystem of tools </h2>
+
+<p>
+The core Git project is just a command-line tool, but Git exploded in popularity
+in the early 2010s thanks to <a href="{{< relurl "tools/hosting">}}">Git hosting services</a>
+like GitLab, GitHub, and more.
+</p>
+
+<p>
+Since Git was created, many
+<a href="{{< relurl "tools/guis" >}}">GUIs</a>, editor integrations,
+and
+<a href="{{< relurl "tools/command-line" >}}">command line tools</a>
+have been built to make working with Git more convenient.
+You favorite developer tools might already have a built-in Git integration.
+</p>
+
+<h2 id="free-and-open-source">Free and Open Source</h2>
+
+<p>
+  Git is released under the <a href="https://opensource.org/licenses/GPL-2.0">
+  GNU General Public License version 2.0</a>, which is an
+  <a href="https://opensource.org/docs/osd">open source license</a>.
+  The Git project chose to use GPLv2 to guarantee your freedom to
+  share and change free software---to make sure the software is
+  free for all its users.
+</p>
+
+<p>
+  However, we do restrict the use of the term "Git" and the
+  <a href="{{< relurl "community/logos" >}}">logos</a> to avoid confusion. Please see our
+  <a href="{{< relurl "about/trademark" >}}">trademark</a> policy for details.
+</p>
+
+
+</div>
+