Change the extension name to "P.JS Developer Signer"

[jeepso]

A request for changing extension name to be changed to "P.JS Developer Signer" (can be something similar as long as the name doesnt include 'Polkadot' and "Wallet").

Almost the entire ecosystem agrees that naming it Polkadot.js creates problem for onboarding new people. As the extension showing up as one of the first results when searched for Polkadot wallet. Changing its name to Developer Signer will make it more clear for newcomers on how the extension is intended to be utilized.

[Tbaut]

While this has been discussed in various channels, it needs to be coordinated and thought through, by the maintainers (currently Parity). We should ask ourselves things like:

• What happens if you're a new user, and follow a tutorial telling you to install this extension, this could be a really bad UX if links are broken, or there's no mention of the name change in the news.
• Should the website url change
• Do we have access to the website credentials to do a redirect/kill the SEO
• Should we promote/redirect to the Polkadot > Wallets website instead (https://polkadot.network/ecosystem/wallets/)
• Shoudl pjs apps be renamed at the same time