Create new `release-0.10` branch and publish v0.10 docs

[RichieEscarez]

Blocking items before creating new branch:

• Finish removing 'build' from doc set:
  - update redirects now that docs/build is gone website#99
  - remove build folder for good #1942
• Fix hardcoded URL so that they point to the correct repo branch/release dynamically populate the correct repo branch #1945

Create new release-0.10 branch:

• Steps 2 - 5 @ [WIP] Need "Docs release process" content #1344

To publish:

• Update build scripts add release-0.10 to the docs builds as latest version website#100

[RichieEscarez]

New branch created: https://github.com/knative/docs/releases/tag/v0.10.x

[RichieEscarez]

v10 ready for publishing (pending a followup LGTM). closing