Create PR from when triggered by webhook

[dankohn]

As CNCF adds new members to Salesforce, we want to be able to automatically create pull requests with the new member's info.

1. Create a GitHub Action that listens for a webhook from the Linux Foundation Salesforce.
2. Define an API of the possible keys to be added, changed, or removed.
3. When a webhook POST is received, CNCF-Bot should create a branch with the new or changed information and open a PR.
4. Demonstrate how you can use a set of curl commands to show that all the functionality is working.

The initial version should support creating, removing, or updating a member. Additionally, it should support adding a member to be a KCSP or KTP. If the SVG is included in the POST, that also needs to be written to hosted_logos, in addition to modifying landscape.yml.

Once things are working on this side, we'll have a Salesforce expert implement the triggers that call out to the webhook when CNCF members change: https://salesforce.stackexchange.com/questions/64253/creation-of-a-public-api/64260#64260 https://salesforce.stackexchange.com/questions/93831/i-need-to-integrate-an-external-system-with-salesforce-using-webhooks/180199 https://moometric.com/integrations/sf/salesforce-visual-workflow-plugin-post-json-callout-external-webservice/ https://stackoverflow.com/questions/13121688/web-hook-in-salesforce