Add in-line file handling capabilities

Add ability to provide in-line file handling. Supports TXT, PDFs, MD, HTML (BeautifulSoup), PNG/JPEG.

Summarize the following website: {{http://example.com}}
Correct any spelling in the following: {{/path/to/file.txt}}
What do you make of this image? {{/path/to/picture.png}}

Supports multiple instances and use cases as well:

What differences do you see in {{/file1}} and {{/file2}}.
Also, who won last nights game? {{https://sportsnews.com/myteam}}

Full Changelog: v1.0.7...v1.0.8