Add more benchmarking content in FRAME

[nuke-web3]

Final student feedback suggests from this question:

What other topics would you like to have been covered by the Academy?

More practical/hands-on content on benchmarking was commonly requested and is only a place holder now. I think as reference Shawn's videos mentioned here could be drawn from but updated as/if needed for 2D weight considerations.

Perhaps a workshop where a simple pallet with working but very inefficient logic and use of storage is benchmarked, compared to weights for a simple but efficient pallet to suggest something is wrong in our example, then the example is refactored and re-benched.