Add beamFoam sister repository documentation

[Seevanibali]

Summary

• add a new top-level Sister Repositories section with beamFoam as the first project
• add beamFoam overview, installation, and user documentation pages
• add navigable workflow guides for the three benchmark tutorials from the beamFoam paper
• include the new section in Markdown lint and link-check workflows

Review requested

This is opened as a draft PR to agree on the proposed website information architecture and documentation depth before merge. In particular, please review:

• placement of Sister Repositories between Documentation and Support
• beamFoam section structure: Overview, Installation, Documentation, Tutorials
• whether the three detailed benchmark tutorial guides should live on the solids4Foam website
• whether the current level of detail and terminology are appropriate

Validation

• Jekyll site build completed successfully
• sidebar navigation and all four beamFoam tutorial URLs rendered successfully
• Markdown lint completed with zero errors
• internal links, images, frontmatter, and external source-case links were checked

Related beamFoam repository documentation PR: solids4foam/beamFoam#37

[philipcardiff]

This all looks great.

One general comment is:

• In solids4foam, most of the tutorial README.md files are located in the solids4foam directory, which is added as a submodule to the website directory; then, symlinks are added in the website pointing to these files. In that way, the READMEs live with the cases themselves rather than on the website. Do you want to make this change?

[philipcardiff]

This looks great and oculd be merged as is, but I suggest you address the minor comments above before we merge it, along with any comments Ivan has.

[Seevanibali]

This all looks great.

One general comment is:

• In solids4foam, most of the tutorial README.md files are located in the solids4foam directory, which is added as a submodule to the website directory; then, symlinks are added in the website pointing to these files. In that way, the READMEs live with the cases themselves rather than on the website. Do you want to make this change?

Sure Philip.

See the new changes:

1. Added imported/beamFoam as a Git submodule and replaced the duplicated website tutorial pages and images with symlinks to the corresponding files in the beamFoam repository.

2. The submodule is temporarily pinned to commit solids4foam/beamFoam@f9a31ab because the required documentation changes have not yet been merged into main. I will update the pointer to the appropriate commit once the PR is merged.

[iBatistic]

I went through the proposed changes, and everything looks good to me.

The placement of the Sister Repositories section seems appropriate. It also makes sense to keep the three tutorials on the s4f page as the beam repo does not have its own page.

I do not see anything that needs to be changed or improved at this stage. Nice work!