Updating docs

[vickysharma0812]

This pull request adds a comprehensive set of test cases and supporting files for the study and demonstration of the Dirichlet boundary condition (DirichletBC) class in a finite element codebase. It introduces new Fortran test programs, TOML configuration files, Lua user function scripts, and a mesh generator, all organized to facilitate the testing and documentation of boundary condition functionality.

The most important changes are:

Test Programs and Configurations for DirichletBC:

• Added three new Fortran test programs (test1.F90, test2.F90, test3.F90) that demonstrate and validate the usage of the DirichletBC class with different types of boundary conditions, including constant and user-defined space-dependent values. Each test is paired with a corresponding TOML configuration file (test1.toml, test2.toml, test3.toml) specifying domain, field, and boundary condition details. [1] [2] [3] [4] [5] [6]

• Added Lua scripts (test2.lua, test3.lua) that define user functions for space-dependent Dirichlet boundary conditions, referenced in the TOML files and called from the Fortran test programs. [1] [2]

Mesh Generation and Supporting Files:

• Introduced a new mesh generator program (mesh.F90) that creates a simple square mesh and exports it in both .msh and .h5 formats, which is then used by the test cases.

• Added build configuration files (runner.toml for the main directory and mesh subdirectory) to facilitate reproducible builds and testing. [1] [2]

Example and Commented Configuration:

• Added an additional commented TOML configuration (test200.toml) that serves as an example for further boundary condition setups, including commented-out Neumann and Dirichlet BC sections.

Documentation and Minor Fixes:

• Fixed a minor typo in the README.md documentation regarding the deploymentBranch configuration.