Using GGG: use a unordered list for GGG-specific PR guidance

In a subsequent commit we want to mention that it is prefered to use an
empty desccription for a single commit PR, since the description is
copied as an in-patch commentary and having the same text twice (once in
the commit messge and once in the in-patch commentary) decreases
the signal-to-noise ratio for reviewers.

Before doing so, let's convert part of the first paragraph of the "How
can you use GitGitGadget?" section into an unorderded list. This will
make the text clearer when we mention single commit PRs later.

Author: phil-blain

index.html

@@ -100,10 +100,13 @@ <h2>How can you use GitGitGadget?</h2>
 				So you cloned <a href="https://github.com/git/git">https://github.com/git/git</a> and implemented a bug fix or a new feature?
 				And you already pushed it to your own fork?
 				Good, now is the time to direct your web browser to <a href="https://github.com/gitgitgadget/git">https://github.com/gitgitgadget/git</a> (or to <a href="https://github.com/git/git">https://github.com/git/git</a> ) and to open a Pull Request.
-				Please make sure to use a descriptive Pull Request title and description; GitGitGadget will use these as the subject and body of the cover letter (check out the <a href="https://git-scm.com/docs/MyFirstContribution">MyFirstContribution</a> tutorial if you are not familiar with this terminology).
-				You can CC potential reviewers by adding a footer to the PR description with the following syntax:
-			</p><p>
-				<code>CC: Revi Ewer &lt;[email protected]&gt;, Ill Takalook &lt;[email protected]&gt;</code>
+				A few things to note about a GitGitGadget Pull Request:
+				<ul>
+					<li>Please make sure to use a descriptive title and description; GitGitGadget will use these as the subject and body of the cover letter (check out the <a href="https://git-scm.com/docs/MyFirstContribution">MyFirstContribution</a> tutorial if you are not familiar with this terminology).</li>
+					<li>You can CC potential reviewers by adding a footer to the PR description with the following syntax:</br>
+					<code>CC: Revi Ewer &lt;[email protected]&gt;, Ill Takalook &lt;[email protected]&gt;</code>
+					</li>
+				</ul>
 			</p><p>
 				You will also want to read <a href="https://git-scm.com/docs/SubmittingPatches">Git's contribution guidelines</a> to make sure that your contributions are in the expected form, as well as the project's <a href="https://github.com/git/git/blob/master/Documentation/CodingGuidelines">coding guidelines</a>.
 				You might also want to read the <a href="https://git-scm.com/docs/gitworkflows">gitworkflows</a> manual page to understand how your contributions will be integrated in Git's repository, as well as <a href="https://github.com/git/git/blob/todo/MaintNotes">this note from Git's maintainer</a>.