🐛 Bug: Endless loop if line contains "\`"

### Bug Report Checklist - [x] I have tried restarting my IDE and the issue persists. - [x] I have pulled the latest `main` branch of the repository. - [x] I have [searched for related issues](https://github.com/JoshuaKGoldberg/sentences-per-line/issues?q=is%3Aissue) and found none that matched my issue. ### Expected The analyzer should correctly handle input such as: ```markdown Path to directory: `C:\Directory\` ``` ### Actual The analyzer enters an infinite loop when a line contains a backslash (\). Example file content: ```markdown Path to directory: `C:\Directory\` ``` ### Additional Info _No response_