markdown-include is GPL licensed.
Also, rewrite it as a block processor, so that it works correctly
inside indented blocks.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
The docs for this can easily be combined into 4 steps. For
uncomplicated setups, 4 seems to be like a good number.
Again, I have no way of verifying the correctness of the instructions
here because Airbrake doesn't let you do anything till you specify
your credit card information, which I didn't want to.
With minor fixes by eeshangarg!
Eeshan: I decided to remove the screenshot. It looks very old and
was blurry and the instructions were very screenshot-agnostic
anyway!
I couldn't update the screenshot because Airbrake doesn't even let
you use the free trial till you give them your credit card info,
which I didn't want to do!