Documentation: Add missing text about new landscape variable 44

newlandscape_landscape_type

docs/newgrf-newlandscape.html

@@ -107,6 +107,9 @@
 	<h4 id="newlandscape_tile_hash">Tile hash (43, or mappable variable: newlandscape_tile_hash)</h4>
 	<p>Hash value derived from the coordinates of the tile, suitable for pseudo-randomising graphics.</p>
 
+	<h4 id="newlandscape_landscape_type">Landscape type (44, or mappable variable: newlandscape_landscape_type)</h4>
+	<p>The landscape type, this currently only has the value 0: rocky tiles.</p>
+
 	<h4 id="roadstop_land_info_nearby_tiles">Land info of nearby tile (60, or mappable variable: newlandscape_land_info_nearby_tiles)</h4>
 	<p>This has the same value as <a href="https://newgrf-specs.tt-wiki.net/wiki/VariationalAction2/Industry_Tiles#Land_info_of_nearby_tiles_.2860.29">industry tile (feature 9) variable 60</a>.</p>