Remove redundant words in sentence

The words "HTML documentation" were duplicated in the base presskit,
and turns out they have been so since the v11 presskit.  This fixes
the v18 presskit base but the older ones are left as they are historic
records of what was published at the time.

Author: Daniel Gustafsson <[email protected]>
Reported-by: "William Sescu (Suva)" <[email protected]>
Discussion: https://postgr.es/m/ZR0P278MB02510DC8731F636750D80CA8E8E3A@ZR0P278MB0251.CHEP278.PROD.OUTLOOK.COM

Author: danielgustafsson

templates/pages/about/press/presskit18/base.html

@@ -105,7 +105,7 @@ <h2>Where to Download</h2>
 {% block presskit_docs %}
 <h2>Documentation</h2>
 <p>
-  PostgreSQL 18 comes with HTML documentation HTML documentation as well as man
+  PostgreSQL 18 comes with HTML documentation as well as man
   pages, and you can also browse the documentation online in both
   <a href="/docs/18/">HTML</a> and <a href="/files/documentation/pdf/18/postgresql-18-US.pdf">PDF</a> formats.
 </p>