Develop a Spelling Correction application that provides users with the ability to input misspelled words or upload text files for automatic correction. The application should include both a web$-$based interface and backend processing using Flask and Python libraries.

Requirements:

Web Interface $(3$ Marks$)$

Front$-$end Development:

Create a web$-$based front$-$end using HTML and JavaScript.

Include an input field for users to manually enter misspelled words.

Provide a file upload option allowing users to upload a text file for batch correction.