Consistent URL endings

[fsimonis]

We are mixing .html with more modern endling-less URLs, which leads to confusion in search engines as they are indexed as separate pages.

We should decide which version we want to stick to, make it consistent and ideally enforce it.

Example:

• https://precice.org/about and https://precice.org/about.html serve the same about.html.
• https://precice.org/ , https://precice.org/index and https://precice.org/index.html serve the index.html

What we need to choose:

1. without ending https://precice.org/about
2. with ending https://precice.org/about.html

What we need to do after the decision:

• Adjust canonical metadata
• Fix sitemap (may require changing permalinks)
• Fix links

[MakisH]

What happens to links from external resources? Can we have redirects both in case we rename about -> about.html and about.html -> about?

[fsimonis]

I am honestly not sure. This behaviour seems to dependent on how the HTTP-server is configured.