Make things work with LiveServer

[asinghvi17]

Set clean=false in makedocs and md_output_path="." in MarkdownVitepress to do this.

Changes:

• If md_output_path is ".", skip copying
• Allow kwargs in run_vitepress_command
• dev_docs has --force
• Check that files don't have the same path (this can be done better via Base.samefile