Update markdown-it-linkify-images to v2.0.0

[jovyntls]

What is the purpose of this pull request?

• Documentation update
• Bug fix
• Feature addition or enhancement
• Code maintenance
• Others, please explain:

Fixes #671

Overview of changes:
Update markdown-it-linkify-images to v2.0.0

Anything you'd like to highlight / discuss:

• The =WxH and =Wx syntax are now working
• However, =xH doesn't work because { imgClass: 'img-fluid' } sets the height attribute of the image to auto, which seems to be overriding the user-defined height.

Testing instructions:

These work:
![](https://vuejs.org/images/logo.png =20x20)
![](https://vuejs.org/images/logo.png =20x)
<panel header="**width & height** :rocket: ![](https://vuejs.org/images/logo.png =20x20)"> ...  </panel>
<panel header="**width** ![](https://vuejs.org/images/logo.png =20x)" type="seamless"> ...  </panel>

These don't work (`=xH`):
![](https://vuejs.org/images/logo.png =x20)
<panel header="**height** :rocket: ![](https://vuejs.org/images/logo.png =x20)" type="seamless"> ...  </panel>

Proposed commit message: (wrap lines at 72 characters)

Update markdown-it-linkify-images to v2.0.0

markdown-it-linkify-images at v1.1.1 overrides image width and height
attributes.

Let's upgrade to v2.0.0 which fixes this problem.

---

Checklist: ☑️

• Updated the documentation for feature additions and enhancements
• Added tests for bug fixes or features
• Linked all related issues
• No unrelated changes

[jonahtanjz]

Thanks @jovyntls for the fix.

Seems like =WxH does not set the height as well and img-fluid is needed to ensure that the images are responsive. Another issue is if the specified width is larger than the parent container's width, then img-fluid will also limit the width as well. With that I think this should be the behaviour to ensure that the images do not overflow.

Perhaps the documentation can be updated to inform the users of the limitations mentioned above?

[jonahtanjz]

Thanks @jovyntls!

LGTM 👍