[BUG] Update wallet selector docs

[PiVortex]

Description

Update the wallet selector docs to support the new lovely version with the signAndSendTransaction method abstracted

Page URL

https://docs.near.org/tools/wallet-selector

Impact

• [x] Incorrect information
• [ ] Missing information
• [ ] Unclear explanation
• [ ] Broken link
• [ ] Code example doesn't work
• [ ] Other (please specify in description)

Suggested Fix

Update docs to new wallet selector version. Show usage of methods