HammerJS depends on CommonJS - bailout warning

[davidzwa]

As most of us now use Angular 10, they will have started to notice the new CommonJS bailout warning for libraries which dont uphold the standard. As HammerJS is a must for us, we can only provide the tip to suppress the warning.

[davidzwa]

Added to readme

Known problems

• HammerJS is known to give a CommonJS bailout warning for Angular 10 when compiling. To suppress this warning add the following to your angular.json:

projects:project-name-here:architect:build:options:allowedCommonJsDependencies: { ..., "hammerjs", ...}

or put differently, add hammerjs to allowedCommonJsDependencies for the @angular-devkit/build-angular:browser builder specification:

"allowedCommonJsDependencies": [
    "hammerjs"
],