Set JANET_MANPATH environment variable while installing.
JPM on windows currently installs its manpage to C:\ directly because this isn't set when installing Janet through the MSI installer
<Condition>ALLUSERS=1</Condition>
<Environment Id="PATH_PERMACHINE" Name="PATH" Value="[BinDir]" Action="set" Permanent="no" System="yes" Part="last"/>
<Environment Id="JANET_BINPATH_PERMACHINE" Name="JANET_BINPATH" Value="[BinDir]" Action="set" Permanent="no" System="yes"/>
+ <Environment Id="JANET_MANPATH_PERMACHINE" Name="JANET_MANPATH" Value="[DocsDir]" Action="set" Permanent="no" System="yes"/>
<Environment Id="JANET_PATH_PERMACHINE" Name="JANET_PATH" Value="[LibraryDir]" Action="set" Permanent="no" System="yes" />
<Environment Id="JANET_HEADERPATH_PERMACHINE" Name="JANET_HEADERPATH" Value="[CDir]" Action="set" Permanent="no" System="yes"/>
<Environment Id="JANET_LIBPATH_PERMACHINE" Name="JANET_LIBPATH" Value="[CDir]" Action="set" Permanent="no" System="yes"/>
<Condition>NOT ALLUSERS=1</Condition>
<Environment Id="PATH_PERUSER" Name="PATH" Value="[BinDir]" Action="set" Permanent="no" System="no" Part="last"/>
<Environment Id="JANET_BINPATH_PERUSER" Name="JANET_BINPATH" Value="[BinDir]" Action="set" Permanent="no" System="no"/>
+ <Environment Id="JANET_MANPATH_PERUSER" Name="JANET_MANPATH" Value="[DocsDir]" Action="set" Permanent="no" System="no"/>
<Environment Id="JANET_PATH_PERUSER" Name="JANET_PATH" Value="[LibraryDir]" Action="set" Permanent="no" System="no" />
<Environment Id="JANET_HEADERPATH_PERUSER" Name="JANET_HEADERPATH" Value="[CDir]" Action="set" Permanent="no" System="no"/>
<Environment Id="JANET_LIBPATH_PERUSER" Name="JANET_LIBPATH" Value="[CDir]" Action="set" Permanent="no" System="no"/>
