Docker.github.io: Add alt text to all images which are missing it

[mdlinville]

Problem description

For accessibility, it is good for all images to have alt text.

Do a search for the following string and add the alt text into the empty brackets:

![](

For instance, an image with missing alt text might look like:

![](foo.png)

And to fix it, you'd change it to something like:

![an example of foo](foo.png)

it's best if the alt text is useful to someone who can't actually see the image, but may be using a screen reader or other assistive text. So don't just repeat the image name or something like that.

This is not a difficult task but will take some time due to considering the right alt text to use for each image.

[bhavin192]

I will work on this.

[bhavin192]

@mstanleyjones There are 577 instances of ![]( not all needed to be replaced though.
is that okay if I create a WIP PR ?

[mdlinville]

Absolutely! If it has WIP in the title we won't consider it for merge yet.