docs: clean up API-CHANGELOG.md

[intelliot]

High Level Overview of Change

Reorganize the contents of API-CHANGELOG so that the newest (and thus most relevant) information is at the top (i.e., reverse chronological order within each of the two sections, API Versions and XRP Ledger server versions)

Context of Change

A reasonable follow-up would be documentation of how/when the full/accounts parameters will be deprecated and eventually removed. Ref: https://github.com/XRPLF/clio/issues/1537

Type of Change

• [x] Documentation update

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 76.2%. Comparing base (b6391fe) to head (a1c9502). Report is 4 commits behind head on develop.

Additional details and impacted files

@@            Coverage Diff            @@
##           develop   #5064     +/-   ##
=========================================
- Coverage     76.2%   76.2%   -0.0%     
=========================================
  Files          760     760             
  Lines        61550   61550             
  Branches      8123    8125      +2     
=========================================
- Hits         46884   46881      -3     
- Misses       14666   14669      +3     

see 4 files with indirect coverage changes

[intelliot]

Trivial: documentation only, no code change