GFM is Github Flavored Markdown and is an extension of Markdown syntax. It should not be presumed to be supported except when writing markdown that will be displayed on Github. You have to ensure it is supported, otherwise. For example, if you are building a Markdown processing pipeline, you would need to incorporate it (like via the remark-gfm plugin).
A paragraph with an internal link to resources section ^a8c7f2
A paragraph with an [internal link to resources section](#Resources)
You can also link to other page's header's in some systems.
Obsidian has a bug related to reference-style links ^f23906
A paragraph with a reference-style link.
A paragraph with [a reference-style link]. : https://www.gatlin.io
- titled: wow
GFM supports footnotes via a reference-like syntax.
A[^1] sentence.[^2] [^1]: Footnote one [^2]: Footnote two, which is also multi-line