Populate an initial Arbitrum collection from crypto-ecosystems data

[ccerv1]

This is enabled by #37 (Any Electric Capital defined crypto-ecosystem can be turned into a Collection).

There are ~200 projects listed as sub_ecosystems for Arbitrum. Some of these already exists as projects in OSS Directory. Others are new.

Implementing the process in #37, submit a single PR to oss-directory that includes:

• an Arbitrum project file
• an Arbitrum collection file
• a new/updated project file for all project items included in the sub_ecosystems array
• a report that summarizes the results of the project updates, specifying for each project whether it was created, updated, or skipped (already exists in OSS Directory with up-to-date GitHub data in it)