自动生成 .gitignore

默认情况下，mix new <projectname> 将在项目根目录中生成一个适用于 Elixir 的 .gitignore 文件。

# The directory Mix will write compiled artifacts to.
/_build

# If you run "mix test --cover", coverage assets end up here.
/cover

# The directory Mix downloads your dependencies sources to.
/deps

# Where 3rd-party dependencies like ExDoc output generated docs.
/doc

# If the VM crashes, it generates a dump, let's ignore it too.
erl_crash.dump

# Also ignore archive artifacts (built via "mix archive.build").
*.ez