Fix duplicate text area bug

[Kostis-S-Z]

What's changing

Make text areas distinct to prevent streamlit from crashing when the content is identical.
The low-hanging fruit solution was to simply change the "pre-text" of the areas to be different so from:
Total Length: for both to Number of characters before cleaning: and Number of characters after cleaning:

For more info check #43 .

Closes #43

How to test it

Steps to test the changes:

1. Run demo app
2. Create empty file file.md and inside write This is an example
3. Upload file to app
4. No crash 🎉

Additional notes for reviewers

~

I already...

• Tested the changes in a working environment to ensure they work as expected
• Added some tests for any new functionality
• Updated the documentation (both comments in code and under /docs)

[daavoo]

Nice catch!