Update the readme, and convert it to Markdown.

Change the creator to Mozilla so that Vlad doesn't get all the complaints.
Remove the empty options.xul.
And remove the XPI, cause we don't need to keep binaries around!
Fixes #39.

Makefile

@@ -1,12 +1,11 @@
 
 SOURCES = \
-	README.txt \
+	README.md \
 	bootstrap.js \
 	chrome.manifest \
 	groups.jsm \
 	install.rdf \
 	multiselect.jsm \
-	options.xul \
 	override-bindings.css \
 	skin/* \
 	tabdatastore.jsm \

README.md

@@ -0,0 +1,24 @@
+# TabCenter <a href="http://testpilot.dev.mozaws.net/experiments/tabcenter"><img align="right" src="https://img.shields.io/badge/available_on-Test_Pilot-0996F8.svg"></a>
+
+
+Tabbed browsing is a concept that has existed for a long time without
+being seriously re-evaluated. In that time, browsing behaviors have
+changed. The web is now the central interaction point on desktop and
+laptop computers. For many users, their browser is the only application
+they ever open.
+
+Tab Center is an attempt to solve some of the issues that have emerged
+from the way people use tabs (most notably the “too many tabs” problem)
+and provide a more versatile UI basis for future innovation.  The first
+version of this Firefox add-on arranges tabs in a vertical rather than
+horizontal fashion.  It is heavily inspired by and borrows ideas from the
+excellent VerticalTabs add-on.
+
+Feel free to [install the add-on][784891c9], read
+[the full proposal][93e83452], file [a new bug][94aea942], or maybe
+[fix some][7c43e6dd]!
+
+[784891c9]: https://people.mozilla.org/~bwinton/TabCenter/tab-center.xpi "A link to the add-on."
+[93e83452]: https://mozilla.invisionapp.com/share/GT22ZN6QW#/screens "The full multi-phase spec."
+[94aea942]: https://github.com/bwinton/VerticalTabs/issues/new "Make a new GitHub issue."
+[7c43e6dd]: https://github.com/bwinton/VerticalTabs/issues "The big list of issues."

install.rdf

@@ -7,7 +7,8 @@
     <em:name>Tab Center Test</em:name>
     <em:version>1.9</em:version>
     <em:homepageURL>https://github.com/bwinton/VerticalTabs</em:homepageURL>
-    <em:creator>Vlad Vukicevic</em:creator>
+    <em:creator>Mozilla</em:creator>
+    <em:contributor>Vlad Vukicevic</em:contributor>
     <em:contributor>Darrin Henein</em:contributor>
     <em:contributor>Philipp von Weitershausen (original author)</em:contributor>
     <em:contributor>SHIMODA Hiroshi (creator of Tree Style Tab)</em:contributor>