[web] First draft of the Beginner Guide

web/content/docs/_index.md

web/content/docs/tools/post-processing/_index.md

...ntent/docs/tools/post-processing/paraview-on-eve/index.md

web/content/docs/userguide/basics/cli-arguments/index.md

web/content/docs/userguide/basics/container/index.md

web/content/docs/userguide/basics/conventions/index.md

web/content/docs/userguide/basics/jupyter-notebooks/index.md

web/content/docs/userguide/basics/project-file/index.md

web/content/docs/userguide/basics/project_file_intro.md

web/content/docs/userguide/basics/quadrature.md

...ntent/docs/userguide/basics/working_with_project_files.md

web/content/docs/userguide/blocks/_index.md

web/content/docs/userguide/blocks/boundary_conditions.md

web/content/docs/userguide/blocks/curves.md

web/content/docs/userguide/blocks/figures/curve.drawio

web/content/docs/userguide/blocks/figures/curve.svg

web/content/docs/userguide/blocks/geometry.md

web/content/docs/userguide/blocks/intro.md

web/content/docs/userguide/blocks/linear_solvers.md

web/content/docs/userguide/blocks/media.md