Green's Open Problems #95

### What is the conjecture
https://people.maths.ox.ac.uk/greenbj/papers/open-problems.pdf#problem.95

(Solved) Are a positive proportion of positive integers a sum of two palindromes?

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

* ams-11

### 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 95 in the linked Green's Open Problems PDF, then inspect existing formalized conjectures in the repository to learn its entry points and conventions. The work is complete when the stated palindrome conjecture is added as a compiling Lean formalization consistent with those conventions.

Written by the indexing model from the issue text.