Add release note generation script

WIP #44

.buildscripts/release-notes.sh

@@ -0,0 +1,40 @@
+# This script generates release notes from the current HEAD to the latest tag.
+# It is rather primitive, relying on formatting conventions in the commit history.
+
+# Example commit message:
+#   Tweak squid positions
+#
+#   I moved the squids a little higher so the
+#   player can dash underneath them if they're
+#   quick enough. That should do it for now.
+#
+#   Fix #32> New enemy: Killer squids now patrol level 2!
+
+# Example usage:
+#   ./release-notes
+
+# Example output:
+#   - New enemy: Killer squids now patrol level 2! (#32)
+
+# ----------
+
+# Used to match commit message lines relevant to release note generation
+# e.g. "Fixes #24> Add a shiny new weapon" or "Fix #12> Fixed a crash that occurred when eating"
+MATCH_ENTRY_LINE="*Fix(es)? #[[:digit:]]+>"
+# Used to capture the release note message and issue number to format later
+# e.g. #Fixes #30> Increase character speed by 25%
+# Group 1: "#30"
+# Group 2: "Increase character speed by 25%"
+CAPTURE_ENTRY_INFO="^ *Fixe\?s\? \(#[[:digit:]]\+\) \?> \?\(.*\)"
+# Used to format the previously captured data
+# e.g. "- Increase character speed by 25% (#30)"
+FORMAT_ENTRY_INFO="- \2 (\1)"
+
+# 1) Print the log from the last tag until now
+# 2) Find all relevant lines,
+# 3) sed wizardry
+# 4) Sort the entries alphabetically
+git log $(git describe --abbrev=0)..HEAD | \
+    grep -E "$MATCH_ENTRY_LINE" | \
+    sed -e "s/$CAPTURE_ENTRY_INFO/$FORMAT_ENTRY_INFO/g" | \
+    sort