Some bug fixed...

[TooSchoolForCool]

• Fix the trailing empty line between paragraph and equation block.
• Fix the Math equation broken issue.
  • Trailing whitespace after \\ leads to error parsing.
  • Incorrectly recognize emphasize annotation in Equation block.
• Handling the exception when uploading a file url.

Try following simple markdown to test your code.

A trailing whitespace after `\\` leads to error
$$
E = mc^2 \\ 
F = ma
$$

Below is an example of incorrectly recognizing emphasize annotation in Equation block.
$$
\text{ratio}_k = \frac{\sum_{i=1}^k \lambda_i}{\sum_{i=1}^n \lambda_i}
$$
This is a local [PDF](./assets/test.pdf).

Note that there is a trailing whitespace at the end of the first equation block (i.e., mc^2 \\ <whitespace>\n).