Update README.md to add the java type and OSON type mappings. (#145)

Author: BidyadharM

ojdbc-provider-jackson-oson/README.md

@@ -14,6 +14,27 @@ in order to use the Oracle JDBC driver's JSON processing capabilities. It, there
 - **Java Types Handling**: Support for various complex and basic Java types during serialization and deserialization.
 - **Jackson Annotation support**: Support for Jackson Annotations. Note: When **@Format** annotation is used, the values are processed as Strings.
 
+## Java type to Oson Mappings
+When the **OSON Provider for Jackson** is used the Java types are stored as their corresponding OSON types. The type
+mapping is given by the following table.
+
+| **Java Type**                              | **Oson Type**      |
+|--------------------------------------------|--------------------|
+| `LocalDateTime`                            | `OSON TIMESTAMP`   |
+| `OffsetDateTime`                           | `OSON TIMESTAMPTZ` |
+| `Period`                                   | `OSON INTERVALYM`  |
+| `Duration`                                 | `OSON INTERVALDS`  |
+| `BigInteger`                               | `OSON NUMBER`      |
+| `Year`                                     | `OSON NUMBER`      |
+| `byte[]`                                   | `OSON byte[]`      |
+| `java.util.Date`                           | `OSON DATE`        |
+| `java.sql.Date`                            | `OSON DATE`        |
+| `Timestamp`                                | `OSON TIMESTAMP`   |
+| `LocalDate`                                | `OSON DATE`        |
+| `Boolean`                                  | `OSON BOOLEAN`     |
+| `UUID`                                     | `OSON UUID byte[]` |
+
+
 ## Installation
 
 All providers in this module are distributed as single jar on the Maven Central