Validation/V1 Schema Megathread

[thomasdavis]

I just bumped the schema version to v1 which makes the cli tool officially v3.

There is going to be problems, therefore this mega thread.

All pre-existing PR's can still be merged (as a part of v3)

Happy to answer and fix all problems, sorry for any inconveniences.

The v1 release of the schema commits to the idea that there won't be official backward incompatibilities -> jsonresume/resume-schema#372

[thomasdavis]

Expedited this change because users using the CLI can set a static version.

But will be changing the official hosting in coming days, so the CLI tool is good testing ground.