Quick Lisp extensions installation

[aartaka]

Is your feature request related to a problem? Please describe.

Our Lispy extensions installation is quite manual as of July 2022 -- git cloning to a certain directory, then ASDF-loading in the config file. Could use some love & automation there.

Describe the solution you'd like

Make a command (or button) to basically make extension installation easy as one action and Nyxt restart. A prototype can be found in https://github.com/atlas-engineer/nyxt/pull/2093.

Describe alternatives you've considered

Relying on package managers?