Revert "Merge branch 'documentation/inital_sizing_readonly' into 'main'"

This merge request follows MR !100 (merged) and updates the documentation for the read-only mode of the initial sizing tool. The previous “artifact size too large” issue has been resolved by moving the UNICADO installer out of the public folder and managing it with Git LFS.

@ellen.seabrooke, could you confirm whether the website now reflects all the changes intended by your previous MR !100 (merged)?