https://powerbi.microsoft.com/en-us/blog/deep-dive-into-powe...
They recently released an update in preview that has a more human readable format:
https://powerbi.microsoft.com/en-us/blog/tmdl-in-power-bi-de...
For comparing semantic models there is ALM Toolkit: http://alm-toolkit.com/
You can also edit BI Models with Tabular Editor which can save objects to storage:
https://tabulareditor.com/downloads
And phi-tools for DevOps: https://pbi.tools/ I’d wait in pbi-tools to start working with Power Bi Developer Mode / Power BI Project files