Reduce size and/or number of copies of IDAES logo

[lbianchi-lbl]

As part of #76, the presence of the idaes-logo.png in the list of file sizes caught my eye:

1. idaes-logo.png is 3.2 MB
2. There are 3 separate copies that I assume are identical (although I haven't checked)

@dangunter Is there a chance you could look into this by e.g.

• [ ] Check if any of the copies can be removed
• [ ] Compress and/or reduce the file size of the required copies

While this wouldn't be enough by itself to fully address #76, these files add up to 9-10 MB so it's not insignificant either.