docs: add godoc comments to all exported functions and methods

mc/level/anvil/level.go

@@ -174,6 +174,7 @@ type Attribute struct {
 	Base float64
 }
 
+// ReadLevelData reads and decodes the level.dat NBT file from a reader.
 func ReadLevelData(r io.Reader) (l Level, err error) {
 	var lDataWrapped struct{ Data Level }
 	err = nbt.ReadFile(r, &lDataWrapped)

mc/level/anvil/mca.go

@@ -52,6 +52,7 @@ type ChunkHeader struct {
 	Chunk, Time [ChunksRegionFile]int32
 }
 
+// ReadChunkHeader reads the chunk header from an MCA region file.
 func ReadChunkHeader(r *os.File) (ch *ChunkHeader, err error) {
 	var h ChunkHeader
 	err = binary.Read(r, binary.BigEndian, &h)