Update CHANGELOG.md

CHANGELOG.md

@@ -1,3 +1,30 @@
+# v0.4.8 - 2021/3/21
+
+### Reduce memory usage at compile time
+
+* go-json have used about 2GB of memory at compile time, but now it can compile with about less than 550MB.
+
+### Fix any encoder's bug
+
+* Add many test cases for encoder
+* Fix composite type ( slice/array/map )
+* Fix pointer types
+* Fix encoding of MarshalJSON or MarshalText or json.Number type
+
+### Refactor encoder
+
+* Change package layout for reducing memory usage at compile
+* Remove anonymous and only operation
+* Remove root property from encodeCompileContext and opcode
+
+### Fix CI
+
+* Add Go 1.16
+* Remove Go 1.13
+* Fix `make cover` task
+
+### Number/Delim/Token/RawMessage use the types defined in encoding/json by type alias
+
 # v0.4.7 - 2021/02/22
 
 ### Fix decoder