docs: use h4 instead of free-standing paragraphs and br-tags

This makes this document a bit more structured, which is generally
considered a good thing for HTML. It will also translate a bit better
into other markup-formats.

Signed-off-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>
diff --git a/docs/install.html b/docs/install.html
index 06c7f28..f4b3edd 100644
--- a/docs/install.html
+++ b/docs/install.html
@@ -35,9 +35,7 @@
 
 <h3>1.1 General</h3>
 
-<p>
-Build system.
-</p>
+<h4>Build system</h4>
 
 <ul>
 <li><a href="https://mesonbuild.com">meson</a> is required when building on *nix platforms.
@@ -51,6 +49,7 @@
 </ul>
 
 
+<h4>Compiler</h4>
 <p>
 The following compilers are known to work, if you know of others or you're
 willing to maintain support for other compiler get in touch.
@@ -63,9 +62,8 @@
 </ul>
 
 
+<h4>Third party/extra tools.</h4>
 <p>
-Third party/extra tools.
-<br>
 <strong>Note</strong>: These should not be required, when building from a release tarball. If
 you think you've spotted a bug let developers know by filing a
 <a href="bugs.html">bug report</a>.