docs: add gnoclient reference & how-to guide

[leohhhn]

Description

This PR adds the reference documentation to the newly added gnoclient.
The reference docs for gnoclient are mostly generated by using a godoc to markdown tool, with slight modifications.

It also adds a how-to guide on how to connect to a Gno.land chain from Go.

Along the way:

• Adds index pages & minor doc improvements for tm2-js & gno-js
• Updates godoc comments in client
• Changes gnoclient function signatures to all be on the same type of receiver (all tests pass). I realize this could've been a different PR but its a small change with no functional/practical impact.

Contributors' checklist...

• Added new tests, or not needed, or not feasible
• Provided an example (e.g. screenshot) to aid review or the PR is self-explanatory
• Updated the official documentation or not needed
• No breaking changes were made, or a BREAKING CHANGE: xxx message was included in the description
• Added references to related issues and PRs
• Provided any useful hints for running manual tests
• Added new benchmarks to generated graphs, if any. More info here.

[codecov]

Codecov Report

Attention: Patch coverage is 62.50000% with 3 lines in your changes are missing coverage. Please review.

Project coverage is 44.83%. Comparing base (8376831) to head (7b1f6bd).
Report is 8 commits behind head on master.

Files	Patch %	Lines
gno.land/pkg/gnoclient/client_queries.go	40.00%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1562      +/-   ##
==========================================
- Coverage   47.55%   44.83%   -2.73%     
==========================================
  Files         388      459      +71     
  Lines       61279    67625    +6346     
==========================================
+ Hits        29144    30322    +1178     
- Misses      29695    34760    +5065     
- Partials     2440     2543     +103     

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[gfanton]

Sounds good! Adding an example of a typical flow with gnoclient would be cool.

[leohhhn]

Latest preview of the PR: https://www.loom.com/share/c51d5d18f0b74e6aa8e7aa388343e1bd?sid=0b12d2e3-2699-4d7a-b1d2-4dbb30deded1

[zivkovicmilos]

Looks good 💯