Update API documentation

[ronaldngounou]

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Key changes:

1. Update Line 168 to address issue #1063

`count` - the actual number of keys within the range when requested. 
Unlike Kvs, it is unaffected by limits and filters (e.g., Min/Max, Create/Modify, Revisions) 
and reflect the full count within the specified range.

2. Improvement to the current documentation by reflecting the latest changes from uptream code base to ensure it remains consistency and similar issues are not occuring. Some information were outdated. Source of my changes: https://github.com/etcd-io/etcd/blob/main/api/etcdserverpb/rpc.proto

Testing

npm run check-links npm run build npm run serve