DuracellEnergizer said:

This editor uses Markdown syntax, which makes it hard to add in-URL parentheses:

Try doing this:

Markdown Syntax Guide said:

Markdown supports two style of links: inline and reference. In both styles, the link text is delimited by [square brackets]

[…]

Reference-style links use a second set of square brackets, inside which you place a label of your choosing to identify the link:

This is [an example][id] reference-style link.

You can optionally use a space to separate the sets of brackets:

This is [an example] [id] reference-style link.

Then, anywhere in the document, you define your link label like this, on a line by itself:

[id]: http://example.com/ “Optional Title Here”

That is:

Square brackets containing the link identifier (optionally
indented from the left margin using up to three spaces);

followed by a colon;

followed by one or more spaces (or tabs);

followed by the URL for the link;

optionally followed by a title attribute for the link, enclosed
in double or single quotes, or enclosed in parentheses.