Add the *.yml extension for YAML, which is commonly used, along with aliases for popular alternate mimetypes for it
<mime-type type="text/x-yaml">
<_comment>YAML source code</_comment>
+ <alias type="application/x-yaml" />
+ <alias type="application/x-yml" />
+ <alias type="application/yaml" />
+ <alias type="text/vnd.yaml" />
+ <alias type="text/yaml" />
+ <alias type="text/x-yml" />
<glob pattern="*.yaml"/>
+ <glob pattern="*.yml"/>
<sub-class-of type="text/plain"/>
</mime-type>
