Add changelog for version 1.2.1

Author: frou

docs/packagecontrol_changelogs/1.2.1.txt

@@ -0,0 +1,5 @@
+-> 1.2.1
+
+FIXED:
+
+- Fixed menu and command palette entries for editing package's Settings & Key Bindings using outdated paths.

messages.json

@@ -1,3 +1,4 @@
 {
-  "1.2.0": "docs/packagecontrol_changelogs/1.2.0.txt"
+  "1.2.0": "docs/packagecontrol_changelogs/1.2.0.txt",
+  "1.2.1": "docs/packagecontrol_changelogs/1.2.1.txt"
 }