Add a new document: CHANGELOG.md (#5)

* Update README.md

Signed-off-by: jinhai <haijin.chn@gmail.com>

* Initiate CHANGELOG.md

Signed-off-by: jinhai <haijin.chn@gmail.com>

CHANGELOG.md

+# Changelog
+
+Please mark all change in change log and use the issue from GitHub
+
+# MatrixBase 0.1.0 (TBD)
+
+## Bug
+
+## Improvement
+
+## Feature
+
+## Task
+
+-   [#4 More documents are needed in Github REPO](https://github.com/matrixorigin/matrixbase/issues/4) 
+

README.md

-MatrixBase is an open-source OLAP database.
\ No newline at end of file
+MatrixBase is an open-source distributed OLAP database.