Clarify in documentation that "#" is or is not a valid "inline comment" token

[danekantner]

HCL specs indicate # is a "line comment" and declares that only the /* */ syntax meets the categorization of an "inline comment"

This is counter-intuitive to how most HCL-based tools actually interpret a # comment when used inline after valid code. Most tools, including Terraform, view a # comment inline after other valid HCL statements to be treated as a valid inline comment (and it is ignored accordingly)