Add functions to support .md files

[suhhee1011]

This pull request resolves #9 . I added a feature to support markdown. Please, let me know by comment if it needs some more features to add or codes need to be fixed.

What I changed:

In generateHTMLStr function,

1. Added regular expression to convert markdown files to HTML files
   • Find bold, italic, anchor, h1, and h2 tags
2. Add conditions to distinguish if it is txt files or MD files
   • Convert bold, italic, anchor, h1, and h2 tags

In strToFile function,

1. Added to let users can convert MD files to HTML.
2. Both MD files and MD files with a folder can convert to HTML

[mkim219]

I have reviewed your PR. There are a few things need to be changed:

• The dist folder should be created in main directory, not the folder that contains md and txt files
• There are unnecessary file you have committed. Please add those files in .gitignore and delete the files on your branch

[suhhee1011]

Thank you for your comment. Based on your comment, I fixed the following:

• Create a dist folder to the main directory instead of inside the text folder. Applied both file type text and MD.
• Added .gitignore and add bin and obj to remove the unnecessary files

[mkim219]

Thank you for your work! LGTM