Add a 5.0 release message

Author: michaelblyons

messages.json

@@ -1,4 +1,5 @@
 {
+	"5.0.0": "messages/5.0.0.md",
 	"5.0.0-beta.01": "messages/5.0.0-beta.md",
 	"4.2.0": "messages/5.0.0-prerelease-invitation.md",
 	"3.1.1": "messages/4.0.0-prerelease-invitation.md"

messages/5.0.0.md

@@ -0,0 +1,37 @@
+# 5.0.0
+
+This is a large syntax change with substantial modification
+to where some keywords are able to be used.
+
+If you find bugs, especially egregious ones that break code
+highlighting further down in the file, please mention them at
+https://github.com/SublimeText/PowerShell/issues and include
+"v5" in the title.
+
+
+## Standout improvements
+
+- Commands are recognized without Verb-Noun format.
+
+- Command arguments are more conscientiously marked,
+  including unquoted strings.
+
+- String contents are sometimes interpreted specially,
+  though not in all cases. Some examples:
+
+    * Here-strings beginning with `using System` are
+      highlighted with C#.
+
+    * Command argument strings recognize wildcards and
+      path separators.
+
+    * Single-quoted strings in certain cases are
+      highlighted with Regular Expressions.
+
+    * Other strings recognize some format placeholders.
+
+- `using` imports can only come at the beginning of a file.
+
+- `meta` scopes are used in more places, which doesn't
+  typically affect highlighting, but sometimes has an
+  effect on ST commands.