Remove outdated changelog & generator script

Reading ML for each version and git log is more useful - also we no longer
track images / done through postmarketos so manging this script / images based
changelog doesn't make sense anymore.
Regenerate changelog for 1.3.0 release
Regenerate CHANGELOG.md for 1.2.0
Bump changelog for 0.1.11 image and regenerate changelog
Regnerate changelog for 0.1.10 release
Regenerate CHANGELOG.md for 0.1.8 release
Add missing commit for 1.1.7 utils
Regenerate changelog for 0.1.7
Regenerate changelog for 0.1.6 release
Add 0.1.5 to changelog and regenerate
Regenerate changelog for 0.1.4 release
Regenerate changelog and add 0.1.3 release
Regenerate changelog
Modify changelog script format and regenerate changelog
Clean up changelog format
Generate CHANGELOG.md