Bootstrap node guide

[LesnyRumcajs]

Summary

One of the use cases for running Forest is having a light-weight bootstrap node. Now, it turned out it might not be as lightweight as we aimed it to be (more work needed), having a guide would still be useful as Forest powers a large chunk of bootstrap nodes for both calibnet and mainnet.

Completion Criteria

• Create a boostrap node guide in the user docs - we could probably salvage https://github.com/ChainSafe/forest/blob/main/documentation/src/bootstrap_node.md

Additional Links & Resources

Migrated from https://github.com/ChainSafe/forest-docs-v2/issues/63