Glad to help :)

I agree when talking big projects, but for a small task like this one it's completely overkill...

Sure but then I might as well use the plain javascript/jquery if I need to maintain code anyway :)

Thanks - I prefer not to use a depicated library for SPO as it can change often :)

Open the workflow in SPD and add it where appropriate. I'm sorry but I don't know how to explain it any more if you all ready are using SPD and have entered the workflow...

Ok then first Set a variable called "LinkToTask" - the content of it should be "Current item url" found under "Workflow context". Then add a replace action replacing "dispform.aspx" with "editform.aspx". Finally use the variable in the mail.

Are you using SharePoint designer or not for your workflow?

True anything but a browser requires changes to the application (outlook for instance).

Uhm that's like a very basic thing to do in a workflow. I assumeed you was familiar with SharePoint designer workflows, but that isn't tha case?

Have you published major version of the masterpage? If not then you need to do it in order to make it avalible :)