Markdown component doesn't handle links to other markdown files when offline

[JulieMarie]

Describe the bug
When creating urls for links to other markdown files in the markdown component, the component assumes an absolute path. For using IPH files offline, the component needs to handle relative paths as well as absolute paths.

To Reproduce
Steps to reproduce the behavior:

1. Change IPH to host file for offline use
2. Try to open a md file that calls out a link to another markdown file
3. Note the error in the console

Expected behavior
User expects to see help files displayed properly whether they are online or offline

Screenshots
Online:

Offline:

Desktop (please complete the following information):

• OS: macOS
• Browser No browser, running Electron app
• Version N/A

Additional context
N/A