“The distribution should contain a file named README with a general overview of the package:
the name of the package;
the version number of the package, or refer to where in the package the version can be found;
a general description of what the package does;
a reference to the file INSTALL, which should in turn contain an explanation of the installation procedure;
a brief explanation of any unusual top-level directories or files, or other hints for readers to find their way around the source;
a reference to the file which contains the copying conditions. The GNU GPL, if used, should be in a file called COPYING. If the GNU LGPL is used, it should be in a file called COPYING.LESSER.”
— GNU Coding Standards, https://www.gnu.org/prep/standards/standards.html#Releases (June 12, 2020)
“Good things to have in the README include:
1. A brief description of the project.
2. A pointer to the project website (if it has one)
3. Notes on the developer's build environment and potential portability problems.
4. A roadmap describing important files and subdirectories.
5. Either build/installation instructions or a pointer to a file containing same (usually INSTALL).
6. Either a maintainers/credits list or a pointer to a file containing same (usually CREDITS).
7. Either recent project news or a pointer to a file containing same (usually NEWS).”
— Software Release Practice HOWTO, https://tldp.org/HOWTO/Software-Release-Practice-HOWTO/distp... (Revision 4.1)