Remixd needs to be removed from Hardhat, Slither, and Foundry pages

[ryestew]

https://remix-ide.readthedocs.io/en/latest/hardhat.html
https://remix-ide.readthedocs.io/en/latest/slither.html
https://remix-ide.readthedocs.io/en/latest/foundry.html

Also other updates may be needed on these pages

@davidekete