The EDoc user guide explains everything you need to know about EDoc comments.

The EDOC_OPTS variable allows you to specify additional EDoc options. Options are documented in the EDoc manual.

A common use for this variable is to enable Markdown in doc comments, using the edown application:

DOC_DEPS = edown
EDOC_OPTS = {doclet, edown_doclet}

To build all documentation, you would typically use:

$ make docs

Do note, however, that EDoc comments will only be generated automatically if the doc/overview.edoc file exists. If you do not want that file and still want to generate doc comments, two solutions are available.

You can generate EDoc documentation directly:

$ make edoc

You can enable automatic generation on make docs by adding the following to your Makefile:

docs:: edoc

In a multi-application project you may want to run EDoc against all applications at the same time, instead of against each applications independently. To do so, you need to configure the EDOC_SRC_DIRS at the end of your Makefile, after including erlang.mk:

EDOC_SRC_DIRS = $(ALL_APPS_DIRS)