fix format and docker version issues

Author: chenliang613

build/How-to-build-carbondata-notebook-docker-image-by-dockerfile.md

@@ -12,7 +12,7 @@ cd build/docker/carbondata-notebook
 ```
 build image：
 ```
-docker build -t carbondata:2.3.0  .
+docker build -t carbondata:2.3.1  .
 ```
 
 ```history

build/How-to-build-carbondata-notebook-docker-image-by-manual.md

@@ -37,10 +37,10 @@ CONTAINER ID   IMAGE                                    COMMAND
 ```
 Add carbondata jar to spark jars directory:
 ```
-docker cp apache-carbondata-2.3.0-bin-spark3.1.1-hadoop2.7.2.jar  305f1277690c:/usr/local/spark-3.1.1-bin-hadoop3.2/jars/
+docker cp apache-carbondata-2.3.1-bin-spark3.1.1-hadoop2.7.2.jar  305f1277690c:/usr/local/spark-3.1.1-bin-hadoop3.2/jars/
 ```
 
-The apache-carbondata-2.3.0-bin-spark3.1.1-hadoop2.7.2.jar is from assembly/target/scala-2.12/ directory of carbondata project.
+The apache-carbondata-2.3.1-bin-spark3.1.1-hadoop2.7.2.jar is from assembly/target/scala-2.12/ directory of carbondata project.
 You can build jar by maven, For example:
 
 ```

format/src/main/thrift/carbondata.thrift

@@ -32,15 +32,15 @@ struct SegmentInfo{
 }
 
 /**
- * Btree index of one blocklet
+ * Btree index of one blocklet for V3 format
  */
 struct BlockletBTreeIndex{
     1: required binary start_key; // Bit-packed start key of one blocklet
     2: required binary end_key;	// Bit-packed end key of one blocklet
 }
 
 /**
- * Min-max index of one blocklet
+ * Min-max index of one blocklet for V3 format
  */
 struct BlockletMinMaxIndex{
     1: required list<binary> min_values; //Min value of all columns of one blocklet Bit-Packed
@@ -49,15 +49,15 @@ struct BlockletMinMaxIndex{
 }
 
 /**
- * Index of one blocklet
+ * Index of one blocklet for V3 format
  */
 struct BlockletIndex{
     1: optional BlockletMinMaxIndex min_max_index;
     2: optional BlockletBTreeIndex b_tree_index;
 }
 
 /**
- * Sort state of one column
+ * Sort state of one column for V3 format
  */
 enum SortState{
     SORT_NONE = 0; // Data is not sorted
@@ -211,7 +211,7 @@ struct FileFooter3{
 }
 
 /**
- * Header for appendable carbon file
+ * Header for appendable carbon file for V3 format
  */
 struct FileHeader{
 	1: required i32 version; // Version used for data compatibility