bob: Update to clarify ambiguity regarding shouted questions about dart

[kytrinyx]

I've submitted a PR to temporarily lock the description of 'bob' so that we can regenerate the exercise READMEs without worrying about getting an out-of-sync description.

This means that the exercises/bob/.meta/description.md file will need to be deleted if the test suite is updated to include the new rule.

[Stargator]

@kytrinyx There's been a few changes to bob. We have an issue to add the fifth rule to the exercise (#84) as well as an issue to address the schema change for input (#95).

Since all three boil down to update the test suite based on the schema, I may wind up closing this ticket and #84, since #95 is more direct.

[kytrinyx]

That sounds great! I wrote a script to check which tracks needed to do the update and submitted an issue based on that... totally forgot that some tracks might already have an open issue.