Add Xray goals

docs/focus/2018-02-12.md

@@ -34,3 +34,14 @@
     - Use fuzzy-finder support internally in our day-to-day workflows to assess usability
 - Treesitter
 - Xray
+  * @nathansobo (and @as-cii part time) will be focusing the next 12 weeks on a prototype for [a new Electron-based text editor](https://github.com/atom/xray). The goal is to explore the viability of radical performance improvements that could be possible if we make breaking changes to Atom's APIs. At the end of the 12 weeks, we will reassess our plans based on what we have managed to learn and accomplish.
+  * Week 1 of 12
+    * Clarify and document goals for the next 12 weeks.
+    * Ensure that the guide matches our current plans.
+    * Refine WebGL based text rendering.
+      * Make sure ASCII text renders correctly without being clipped
+      * Render text correctly on high DPI displays
+      * Use correct API for texture atlas updates
+      * Add mouse-wheel scrolling support
+      * Non-ASCII rendering, using the HarfBuzz text shaping library to detect combining characters
+    * Stretch goal: Switch document encoding to UTF-8 for memory compactness and support multi-byte-aware character indexing.