Check content of code blocks for any sequence of backticks

[susnux]

• Resolves: #88

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CommonMark allows a sequence of backticks within a code block, but the fence has to be at least one backtick longer than the sequence within. See the linked issue for a detailed explanation.

[marijnh]

We're still targeting browsers that don't have String.repeat. But it seems you can easily avoid using that by appending an extra backtick to the matched string itself.

[susnux]

We're still targeting browsers that don't have String.repeat. But it seems you can easily avoid using that by appending an extra backtick to the matched string itself.

Ok rewrote it without String.repeat.

[marijnh]

Thanks!