add script to add links in changelog

scripts/linkify_changelog.py

@@ -0,0 +1,13 @@
+import fileinput
+import re
+
+# This script goes through the provided file, and replaces any " \#<number>",
+# with the valid mark down formatted link to it. e.g.
+# " [\#number](https://github.com/tendermint/tendermint/issues/<number>)
+# Note that if the number is for a PR, github will auto-redirect you when you click the link.
+# It is safe to run the script multiple times in succession. 
+#
+# Example usage $ python3 linkify_changelog.py ../CHANGELOG_PENDING.md
+for line in fileinput.input(inplace=1):
+    line = re.sub(r"\s\\#([0-9]*)", r" [\\#\1](https://github.com/tendermint/tendermint/issues/\1)", line.rstrip())
+    print(line)