Syntax specific setting in Sublime Text

Markdown Settings

{
    // Which file extensions go with this file type?
    "extensions":
    [
        "md",
        "mdown",
        "mdwn",
        "mmd",
        "txt"
    ],

    // Disables horizontal scrolling if enabled.
    // May be set to true, false, or "auto", where it will be disabled for
    // source code, and otherwise enabled.
    "word_wrap": "true",

    // Set to a value other than 0 to force wrapping at that column rather than the
    // window width
    "wrap_width": 80,

    // Set to true to removing trailing white space on save
    "trim_trailing_white_space_on_save": false
}