[DOC] Add docs on nearblocks, fastnear, and pikespeak API

[gagdiez]

Documentation Type

New documentation

What needs documentation?

There are new ecosystem APIs - pikespeak, nearblocks, fastnear - that allow users to easily query data from on-chain activity and assets without the need to build an indexer

We need to find a place for them in our documentation, add some relevant examples and link to their external documentation sites

Acceptance Criteria

• Pikespeak API is documented
• Fastnear API is documented
• Nearblocks API is documented

Resources & References

https://docs.google.com/presentation/d/1t8ru9Lt-PfHulHMBIJ-n0U_DYYDk4tbcfcWpwrXW8hE/edit?usp=sharing

Priority

🔴 P0 : Missing Critical Documentation