switching to changes.md instead of revisions.txt

Author: benfry

build/shared/changes.md

@@ -0,0 +1,13 @@
+# Processing 4.0 alpha 1
+
+### Revision 1270 - 18 January 2019
+
+This is a massive update! With the help of Sam Pottinger, we're working
+to get Processing to run with Java 11.
+
+
+
+***
+
+
+Revisions for Processing 3.x and earlier have been removed. [You can find them here.](https://raw.githubusercontent.com/processing/processing/master/build/shared/revisions.txt)