[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

• 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