Green's Open Problems #91

### What is the conjecture
https://people.maths.ox.ac.uk/greenbj/papers/open-problems.pdf#problem.91

(Solved) Take a random graph $G(n, \frac{1}{2})$. Is there almost surely a bipartition of $G$ into two sets of $n/2$ vertices with the property that 99% of vertices have more neighbours on their own side than on the other?

### [AMS categories](https://github.com/google-deepmind/formal-conjectures/labels?q=ams-)

* ams-05
* ams-60

### Choose either option
- [ ] I plan on adding this conjecture to the repository
- [x] This issue is up for grabs: I would like to see this conjecture added by somebody else

Read problem 91 in the linked Green's Open Problems PDF and review the repository's existing formalized conjecture statements for the expected structure. Formalize the stated random-graph conjecture and add it to the collection; done means the conjecture is represented in Lean and fits the repository's conventions.

Written by the indexing model from the issue text.