doc/go1.15: create go1.15.html

Copied from go1.14.html, with changes redacted back to TODOs following
the model of CL 195058.

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

Updates #33738

Change-Id: I580232805ab7db35935f3e1ba03b720be4796a7e
Reviewed-on: https://go-review.googlesource.com/c/go/+/220278
Reviewed-by: Alexander Rakoczy <alex@golang.org>
Run-TryBot: Alexander Rakoczy <alex@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

doc/go1.15.html

@@ -0,0 +1,73 @@
+<!--{
+        "Title": "Go 1.15 Release Notes",
+        "Path":  "/doc/go1.15"
+}-->
+
+<!--
+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 1.15</h2>
+
+<p>
+  <strong>
+    Go 1.15 is not yet released. These are work-in-progress
+    release notes. Go 1.15 is expected to be released in August 2020.
+  </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="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>