Create a changelog for major user facing changes to the VEDA Hub

[maxrjones]

As discussed in slack, we should create a changelog for major user facing changes to the VEDA Hub. For example, the recent addition of deploying dynamic image building. This is to promote a positive user experience by avoiding surprises and publicizing cool new features. Possibly we could automate some detection of new features by monitoring the VEDA configuration within 2i2c/infrastructure, but this would likely require some manual work as well. I think this would fit in the scientific computing section of the docs.

cc @wildintellect