How to do strikethrough in a reStructuredText file hosted on GitHub?

I am converting a README.md file to README.rst. The reason is, I am going to make a package available to PyPi. I am forced to use .rst.

My conversion is nearly complete, but I have a strikethrough line in my markdown file, e.g.:

~~This text is crossed out~~

which renders on GitHub as crossed out. But I am unable to do this in reStructuredText. A similar post on StackOverflow suggests defining a strike like this:

.. role:: strike    :class: strike

And using something like this in the CSS file:

.strike {  text-decoration: line-through;}

And do strikethrough like this:

:strike:`This text is crossed out`

But the problem is I have no control over CSS file of GitHub.