Mentioning JavaScript in this context is not informative. Note that, Java, C# and C++ are also using the same type of comments. It is in my view not even relevant to mention here that a similar style comments to some programming language are used.

Existing Wording:

FSH follows JavaScript syntax for code comments, with // denoting single-line comments, and the pair /* */ delimiting multiple line comments.

Proposed Wording:

FSH uses // for single-line comments, and the pair /* */ for multiple line comments.