Definition - What does Readme mean?
The readme file is a file that is attached to a software program that contains critical or important information about that program. The readme file is, in a sense, a manual or instructional resource for that program.
Techopedia explains Readme
Readme files can include specific instructions on installation and use. They may also include important disclaimers and warnings about what not to do during program execution. It is helpful to read a readme file attached to a program, in the same way that manufacturers recommend reading any manual attached to any consumer product, for example, an appliance. The name or label “readme” is often seen as related to the labels “eat me” and “drink me” attached to food and drink items in Lewis Carroll’s “Alice in Wonderland” book.