Update README.md
Update README.md

make terminal style consistent
v.1.2.0

- updates `guardian-brand`
- adds `guardian-brand-dark`
Update CHANGELOG.md
Merge branch 'master' into gh-pages
Delete CHANGELOG.md
Remove version number, rely solely on tags
Merge pull request #4 from guardian/simplify-releases

Simplify release process
Use new file naming convention
Update demo styles
Merge pull request #5 from guardian/file-naming

File naming conventions
Remove unnecessary .scss in import
Bring demo file naming in line with other Guss components
Merge branch 'master' into gh-pages
Merge branch 'gh-pages' of github.com:guardian/guss-colours into gh-pages