Connector Builder Landing Page

[lmossman]

Context

Implement the landing page for the connector builder, as shown in this design: https://www.figma.com/proto/F1ljvrJerLoVbNvtejBWid/LOW-CODE-CONNECTOR-BUILDER?page-id=3404%3A119487&node-id=3426%3A123290&viewport=-6573%2C-494%2C2&scaling=min-zoom&starting-point-node-id=3426%3A123290

Note: For now, the middle tile (Load an existing connector) and its corresponding page will not be added. This will be added once the "managing multiple connectors" project is complete.

Acceptance Criteria

A landing page for the connector builder exists with two tiles:

• Import a YAML manifest, which opens the builder in the YAML view containing the imported yaml
• Start from scratch, which for now will just open a blank connector builder

Open question: should we always show this page when going to /connector-builder right now? Or should it only be shown if they don't have anything in local storage?

• Grooming notes: Go with the latter option here to get us incrementally there

[lmossman]

Had one round of review and addressed the feedback, waiting on final review