Deprecation: #76104 - Deprecated single slash comments in TypoScript

See Issue #76104

Description

Double slash one-line comments are standard in many languages. Make them standard for TypoScript, too.

Define:

One-line comments must start with two forward slashes as
the first non-blank characters and should be followed by
a whitespace.

Deprecated:

/ Line comment headed by single slash

Impact

The TypoScript developer receives a deprecation warning with line number.

Affected Installations

Installations using a single slash to indicate a comment.

Migration

Use double slashes (//) or hash (#) for comments in Typoscript.