Typo Update cross-chain-contract-via-l2cdm.md

[mdqst]

I found a typo in the documentation at docs/src/guides/interop/cross-chain-contract-via-l2cdm.md.

In the High level overview section, the sentence:

Players hit a virtual ** *ball* ** back and forth between allowed L2 chains.

contains incorrect formatting for the word "ball". The extra spaces and asterisk should be removed to correct the formatting.

Correct version:

Players hit a virtual **ball** back and forth between allowed L2 chains.

Importance of the Fix:

This fix is important because it ensures the correct formatting for the word "ball" and improves the overall readability of the documentation. Proper formatting enhances clarity and helps avoid any confusion for readers.