languages: Capture escape sequences in C and C++ (#46116)

ozacod created

Before:
<img width="901" height="247" alt="before"
src="https://github.com/user-attachments/assets/95467f0a-e464-44ea-a8f3-bedccf57c6a9"
/>

After:
<img width="967" height="256" alt="after"
src="https://github.com/user-attachments/assets/5eb43918-4348-42d2-9174-3fafd82919d0"
/>

Release Notes:

- Added highlighting for escape sequences for C and C++.

Change summary

crates/languages/src/c/highlights.scm   | 2 ++
crates/languages/src/cpp/highlights.scm | 2 ++
2 files changed, 4 insertions(+)

Detailed changes