Mincong Huang

**Description** There are two underlines in Firefox for titles. **Steps to Reproduce** 1. Use the latest Firefox (85.0.2) 2. Visit https://tianqi.name/blog/ 3. Hover on one blog post title **Expected behavior**...

## Description Currently, we have to provide a `data_source` variable to use the `articles` layout. But that means creating a [collection](https://jekyllrb.com/docs/collections/) explicitly for the articles that we want to show....

## Description Currently, Jekyll TeXt Theme relies on variable `post.key` to [enable the disqus comment](https://github.com/kitian616/jekyll-TeXt-theme/blob/79b42a61bf1fecf49f403159822b623c95eac6aa/_includes/comments-providers/disqus.html#L1) and [uses it as identifier for disqus](https://github.com/kitian616/jekyll-TeXt-theme/blob/79b42a61bf1fecf49f403159822b623c95eac6aa/_includes/comments-providers/disqus.html#L11). Although there is [a warning in the documentation](https://tianqi.name/jekyll-TeXt-theme/docs/en/configuration#comments),...

## Description Currently, when listing many articles in one page, the images won't have the same size (height and width). This happened to my blog page "categories" and "about" when...

Reproduce issue #17 Try overload resolution ambiguity. Not sure if we want to merge this test, but at least I prove the issue exist with it.

This PR upgrades the [Mermaid JS](https://mermaid-js.github.io/mermaid/#/) library to 9.2.2. This allows Jekyll TeXt Theme to support more Mermaid syntax. For example, the sequence diagram [demo](https://mermaid-js.github.io/mermaid/syntax/sequenceDiagram.html) is not supported in 8.0.0....