[release] v0.17.3

[mpourismaiel]

• [x] Update changelog
• [ ] Change Hugo min version in theme.toml
• [ ] Change version
  • [x] /VERSION
  • [x] .seed-config.yaml
  • [x] /package.json
  • [x] /exampleSite/package.json
  • [x] /exampleSite/config.toml
  • [x] /exampleSite/config-dev.toml
  • [x] /exampleSite/content/docs/installation/content.md
  • [x] layouts/partials/head.html

• [x] Create stable release branch vX.X (gets minor, non breaking updates)

• [ ] Migrate various test/production sites to release branch

• [ ] tag alpha, beta releases, if necessary

• [ ] Fix/document remaining bugs/PRs
• [ ] Test sites again

• [ ] Rinse and repeat

• [ ] Update docs to latest release branch
• [x] Create final tag
• [x] Create Github release
• [x] Release notes
• [x] Migrate starter repo
  • [x] Change version
  • [x] /VERSION
  • [x] .seed-config.yaml
  • [x] /config.toml
  • [x] Update submodule
  • [x] Update config.toml (with version and content changes)

  • [ ] Change Hugo version in netlify.toml

• [ ] Test latest release with themes.gohugo.io script
• [ ] Merge latest syna demo/page into about.okkur.org/syna/ (see syna/README for specifics)