Update README
@jnny I've revised the "Building" section of the README. Please review and approve if it looks good to you. Or feel free to copy-edit and make any additional changes to the README and commit them to this update/readme
branch so they are included in this MR.
See my revisions starting at this section, https://gitlab.com/censorship-no/ceno-browser/-/tree/update/readme#-building
Edited by grant