Add Syntax Highlight, QLMarkdown and qView, Edit typora

[LXZE]

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Types of Changes

What types of changes does your PR introduce? Put an x in all boxes that apply

• New addition to list
• Fixing bug in existing item in list
• Removing item from list
• Changing structure (organization) of list

Proposed Changes

Describe each of your changes here to communicate to the maintainers why we should accept this pull request.

1. Add Syntax Highlight and QLMarkdown in Quicklook plugin section.
2. Add qView, an image viewer application in Other Tools section.
3. Remove freeware icon from typora as it is no longer free now. ($14.99 with 15 days free trial)

PR Checklist

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• I have read the CONTRIBUTING guide
• I have explained why this PR is important
• I have added necessary documentation (if appropriate)