message: doc: Document ALLOW_HOST_PACKAGES dependency option
diff: @@ -105,6 +105,10 @@ The following can be set when running make: `make FOO=bar`
  <dd>Don't download/build/cache SQLite</dd>
  <dt>NO_UPNP</dt>
  <dd>Don't download/build/cache packages needed for enabling upnp</dd>
  +<dt>ALLOW_HOST_PACKAGES</dt>
  +<dd>Packages that are missed in dependencies (due to `NO_*` option or
  +build script logic) are searched for among the host system packages using
  +`pkg-config`. It allows building with packages of other (newer) versions</dd>
  <dt>MULTIPROCESS</dt>
  <dd>build libmultiprocess (experimental, requires cmake)</dd>
  <dt>DEBUG</dt>
  