RTF input

[godai78]

Add support for RTF file format input.

It detects and handles stuff properly, but does not fully clean the headings - it cannot detect and remove the {\*\bkmkstart and {\*\bkmkend sequence.

[Copilot]

Pull Request Overview

This PR adds support for RTF file input to the DOCX Splitter, updating both the front-end and back-end handling to accept and process RTF files.

• Updated documentation and error messages in the user manual
• Modified package.json and index.html to include the rtf-parser dependency and accept RTF files
• Added processRtf logic in app.js to parse RTF content and integrated RTF handling along with existing DOCX processing

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
user_manual.md	Added error codes documentation
package.json	Added dependency for RTF file processing
index.html	Updated file input accept attribute
app.js	Implemented RTF processing and extended file format support
README.md	Updated version and description
CHANGELOG.md	Documented new RTF support in changelog

Comments suppressed due to low confidence (1)

index.html:12

• Consider updating the header text to reflect the support for both DOCX and RTF files (e.g. 'Input file and split every header into a new file') to avoid possible confusion.

<h3>Input docx and split every header into a new rtf file</h3>