The README documents wallet adapters twice

[Abioladory123]

Summary

The README has a Wallet Adapters heading inside the API Reference and a second,
separate Wallet Adapters section further down covering Freighter and xBull. A
reader hitting the first one has no idea a fuller treatment exists below.

Two sections with the same name also means updates land in one of them and not
the other, which is how they drift apart.

Acceptance criteria

• The wallet adapter material appears once, in whichever position suits the
  document's flow.
• Nothing unique to either section is lost in the merge.
• Any internal links or the table of contents are updated to match.

Getting started

Fork this repository, clone your fork, and add this repo as upstream:

git clone https://github.com/<your-username>/novatip-sdk.git
cd novatip-sdk
git remote add upstream https://github.com/Novatip/novatip-sdk.git
npm install

Create a branch for this issue:

git checkout -b docs/dedupe-adapter-sections

Suggested commit message:

docs: merge the duplicated wallet adapter sections

Run npm run lint, npm run typecheck, and npm run build before pushing, then open a pull request from your fork against main and link this issue. See the contributing guide for the full workflow.

[glendell03]

I'd like to work on this. I'll merge the two Wallet Adapters sections in README.md — the one under API Reference and the separate Freighter/xBull section further down — into a single section, keeping anything unique from each (the API reference details plus the Freighter/xBull specifics). I'd place it wherever it reads more naturally in the doc flow, likely where the fuller Freighter/xBull content currently lives, and update the table of contents and any internal anchors/links that point at either heading so nothing 404s.

One judgment call: whether the merged section stays under API Reference or moves to its own top-level heading. I'd lean toward its own section since it covers usage, not just API surface, but I'd rather confirm that before writing it up than redo the structure after.

Could you assign me this issue?