Signature help for the escape parser directive should not be formatted in Markdown

[rcjsuen]

var dockerfileLanguageService = require("dockerfile-language-service");
var service = dockerfileLanguageService.DockerfileLanguageServiceFactory.createLanguageService();
var signatureHelp = service.computeSignatureHelp(
    "#escape=",
    { line: 0, character: 8 }
);
console.log(signatureHelp.signatures[0].label);

escape=`\`

As label is typed as a string, we should not be sending information back as Markdown.