Establish a common installation and verification path for PyFEM #17

PyFEM is educational software, so a new user should be able to install it and run an example outside the developer's checkout. At present, installation guidance, tests, package builds, and documentation take partly separate paths. A test run against the source tree can pass even if the installed package or the instructions a student follows fail. When that happens, support begins with reconstructing the student's Python environment rather than examining the model.

A shared uv workflow would give students and instructors a common starting point across different machines. It reduces the amount of Python packaging knowledge needed for a first run, and its speed makes rebuilding an environment more practical while helping a student. It cannot remove every platform difference, but it should make failures easier to reproduce and explain.

The same commands would support future development. CI can check supported Python versions, an installed package, a representative analysis, and the documentation build using the contributor workflow. Coding agents can use those commands when working on future changes, and maintainers can assess their results against the same checks. This makes automated work more useful while reducing drift between the instructions and the tests.

PR #14 contains the proposed implementation. It leaves numerical formulations and example inputs unchanged. Thank you for taking the time to consider this proposal.