TIMES model generator

[olejandro]

Currently the readme states "The ON-TIMES model is based on the TIMES model generator.". Please consider

• changing it to "The ON-TIMES model requires the TIMES model generator to run." or "The ON-TIMES model requires the TIMES model generator to be executed." or similar.
• linking to the TIMES model generato repository on github: https://github.com/etsap-TIMES/TIMES_model
• indicating that it is possible to run / execute the model and check the results using vedaonline https://lma.vedaviz.com/vedaonline/