docs: README/index.md CEX Token example passes invalid `sort` kwarg to cex.token.updates

[martinkersner]

Discovered during review of PR #163 (#163).

The CEX Token Updates example in the README and its docs mirror passes sort="desc", but cex.token.updates accepts no sort parameter (sync datamaxi/resources/cex_token.py and async datamaxi/aio/cex.py both only take page, limit, type). Running the snippet raises TypeError: updates() got an unexpected keyword argument 'sort'.

Locations (out of scope for #163's diff, so left untouched there):

• README.md around line 312-317 (CEX Token Updates block)
• docs/index.md around line 312-317 (same block, README mirror)

Note: the dedicated docs/cex-token.md page was already corrected in PR #163 (the invalid sort kwarg removed from both Sync and Async tabs).

Done when: the sort="desc" line is removed from the cex.token.updates(...) example in both README.md and docs/index.md so the snippet is valid.

[martinkersner]

Fixed in PR #163 (commit 5e7885b) — removed the invalid sort= kwarg from the CEX Token Updates example in README.md (docs/index.md is a symlink to it, so both are covered).