Initial Singularity image definition file

[TrupeshKumarPatel]

This PR is to submit the initial Singularity definition file.

File Tree

(`develop` branch)
.
├── guide.sh
├── README.md
└── singularity
    ├── build.log
    ├── singularity_ngen.def
    └── templates
        ├── extern
        │   └── install_extern_libraries.sh
        ├── guide
        │   └── HelloNGEN.sh
        ├── netcdf
        │   └── install_netcdf_cxx.sh
        ├── ngen
        │   └── install_ngen.sh
        └── t-route
            └── install_t_route.sh

1. guilde.sh : The guide script to run the simulations on the singularity image
2. README.md : Documentation of how to run the model and contribute in development on NGIAB
3. singularity_ngen.def : The singularity definition file to build image
4. build.log : This is the last build log that shows all detailed information about the last image build process.
5. install_extern_libraries.sh : This is helper script to install external NGen module during image building process.
6. HelloNGEN.sh : This is NGen execution script, which runs when the image is being executed by users.
7. install_netcdf_cxx.sh : This is helper script to install latest NetCDF C++ version during image building process.
8. install_ngen.sh : This is helper script to install latest NextGen version during image building process.
9. install_t_route.sh : This is helper script to install latest T-route version during image building process.

Tested On

1. Created on Rocky Linux 9.3 (x86) locally
2. Tested on Rocky Linux 9.3 (x86) locally

TODO

The guide script is still in work in progress to automate download process on the built image from Docker Hub.