minedmap: write info.json file with tilemap metadata

With this change, the new minedmap implementation can generate all
necessary data for the frontend to work.

src/bin/minedmap/main.rs

@@ -1,4 +1,5 @@
 mod common;
+mod metadata_writer;
 mod region_processor;
 mod tile_mipmapper;
 mod tile_renderer;
@@ -9,6 +10,7 @@ use anyhow::Result;
 use clap::Parser;
 
 use common::Config;
+use metadata_writer::MetadataWriter;
 use region_processor::RegionProcessor;
 use tile_mipmapper::TileMipmapper;
 use tile_renderer::TileRenderer;
@@ -27,7 +29,8 @@ fn main() -> Result<()> {
 
 	let regions = RegionProcessor::new(&config).run()?;
 	TileRenderer::new(&config).run(&regions)?;
-	TileMipmapper::new(&config).run(&regions)?;
+	let tiles = TileMipmapper::new(&config).run(&regions)?;
+	MetadataWriter::new(&config).run(tiles)?;
 
 	Ok(())
 }