Ya I have seen doodleipsum, but i would say this is better than that. Even with doodleipsum, you would have to leave your code editor, go to an external website then pick and copy the link you want to use.
With Imgsrc.space just name the picture you want right into your code and it would be magically delivered.
something like - https://imgsrc.space/sunset - would give you a picture of a sunset https://imgsrc.space/computer - would give you a picture of a computer.
It's just like searching on google images but without even leaving your editor.
Also if you use the JS library.this is how easy choosing an image will become-
<img src=". cat"> gives an image of a cat
In my experience while using Imgsrc.space your images would not be cached by the browser, but if you still face any issues. try adding a ? mark at the end with some random query string (even just a ? would be fine) something like https://imgsrc.space/cat?