Make 'public' directory path configurable

[pixelspark]

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

I want to build two products (a client and a server) from the same project. To this end I have two Vite config files with (among others) different entry points. I want to use the public directory to copy over certain files to the client's root directory, but also to copy certain files to the server's root directory. Currently however there is no way to tell Vite to use a different 'public' directory for each build. Judging by the source code, the "public" path seems to be hardcoded:

vite/packages/vite/src/node/build.ts

Line 310 in c2e8806

const publicDir = resolve('public')

Describe the solution you'd like

Allow the "public" directory to be changed from the vite.config.js file. Suggestion:

"publicDir": "name of directory (public by default)"

Describe alternatives you've considered

Instructions on building both server and client with Vite are limited. I might be misusing Vite for this purpose, but I do like to use the same build system for both, so you just have to learn one system. I could use rollup directly for the server build of course.

Additional context
n/a

Very happy with Vite so far!