Create redirections for future obsolete PHP URLs.

[rookiehpc]

The URL to say MPI_Comm_size has changed between the two versions of the RookieHPC website:

• /mpi/docs/mpi_comm_size.php in the original website
• /mpi/docs/mpi_comm_size/index.html in the website v2

When the domain name rookiehpc.com will point to the GitHub Pages website, links pointing to the original website PHP pages will become broken. Create placeholders for such links, typically by creating a file /mpi/docs/mpi_comm_size.php which will redirect to /mpi/docs/mpi_comm_size/index.html.

[rookiehpc]

The initial plan was to recreate dummy PhP files at the locations where the PhP files are on the previous website, and make those dummy files do a page-redirect to their HTML new version.

Example for the MPI_Comm_size mentioned above:

• Create a /mpi/docs/mpi_comm_size.php file in the repo
• Make it do a page-redirect to the /mpi/docs/mpi_comm_size/index.html in the repo

The problem is that files with the PhP extension are never opened on Github Pages websites, even if the actual content is pure HTML. Instead, the file is downloaded by the visitor, which does not trigger the redirect.

Therefore, there is no solution yet to recreate those PhP-ending URLs on the new website. As a suboptimal solution, every single page of the previous website (the one currently occupying the rookiehpc.com domain name) is having a 301 permanently moved redirection to its GitHub pages equivalent.

This will help search engines update their index and no longer show PhP-ending URLs in their results but the HTML equivalent from the repo.

Of course, when the rookiehpc.com domain name will actually point to the rookiehpc.github.io one, there will no longer be 301 permanent redirections and PhP links will then lead to 404 instead. All in all, it only takes a couple of seconds to write "MPI_Comm_size" in the search bar at the top of the page and land on the HTML new page.

The last hope is to find a way for the 404 page to somehow receive the PhP-URL that is now missing, and automatically redirect it to the corresponding new HTML page.