doc/go1.16: start draft release notes

This template is based on CL 220278 and previous ones like it.
Include Compiler and Linker sections proactively, they can be
removed if they don't end up being needed for Go 1.16.

Use two spaces of indentation for TODOs to set a better precedent
for the final text that will take its place.

'relnote -html' does not report any changes at this time.

For #40700.

Change-Id: I096b0ce0d33aaaa6fae9c91c0d2dfb89b9c5e94c
Reviewed-on: https://go-review.googlesource.com/c/go/+/248198
Reviewed-by: Carlos Amedee <carlos@golang.org>

doc/go1.16.html

@@ -0,0 +1,84 @@
+<!--{
+	"Title": "Go 1.16 Release Notes",
+	"Path":  "/doc/go1.16"
+}-->
+
+<!--
+NOTE: In this document and others in this directory, the convention is to
+set fixed-width phrases with non-fixed-width spaces, as in
+<code>hello</code> <code>world</code>.
+Do not send CLs removing the interior tags from such phrases.
+-->
+
+<style>
+  main ul li { margin: 0.5em 0; }
+</style>
+
+<h2 id="introduction">DRAFT RELEASE NOTES — Introduction to Go 1.16</h2>
+
+<p>
+  <strong>
+    Go 1.16 is not yet released. These are work-in-progress
+    release notes. Go 1.16 is expected to be released in February 2021.
+  </strong>
+</p>
+
+<h2 id="language">Changes to the language</h2>
+
+<p>
+  TODO
+</p>
+
+<h2 id="ports">Ports</h2>
+
+<p>
+  TODO
+</p>
+
+<h2 id="tools">Tools</h2>
+
+<p>
+  TODO
+</p>
+
+<h3 id="go-command">Go command</h3>
+
+<p>
+  TODO
+</p>
+
+<h2 id="runtime">Runtime</h2>
+
+<p>
+  TODO
+</p>
+
+<h2 id="compiler">Compiler</h2>
+
+<p>
+  TODO
+</p>
+
+<h2 id="linker">Linker</h2>
+
+<p>
+  TODO
+</p>
+
+<h2 id="library">Core library</h2>
+
+<p>
+  TODO
+</p>
+
+<h3 id="minor_library_changes">Minor changes to the library</h3>
+
+<p>
+  As always, there are various minor changes and updates to the library,
+  made with the Go 1 <a href="/doc/go1compat">promise of compatibility</a>
+  in mind.
+</p>
+
+<p>
+  TODO
+</p>