docs: Updating changelog with missing features

Author: vlastahajek

CHANGELOG.md

@@ -1,9 +1,14 @@
 # Changelog
 ## [in progress]
+### Features
+ - [#147](https://github.com/tobiasschuerg/InfluxDB-Client-for-Arduino/pull/147) - Updated InfluxDB 2 Cloud CA root certificate to _ISRG Root X1_.   
+ Current InfluxDB 2 Cloud CA root certificate _DST Root CA X3_ expires on September 30th 2021!
+ - [#157](https://github.com/tobiasschuerg/InfluxDB-Client-for-Arduino/pull/157) - Added Buckets sub-client for managing buckets in InfluxDB 2. 
+ 
 ### Fixes
- - [#150](https://github.com/tobiasschuerg/InfluxDB-Client-for-Arduino/pull/150) - `HTTPOptions::httpReadTimeout` is also set as the connect timeout for HTTP connection on ESP32. It doesn't work for HTTPS connection yet. 
+ - [#150](https://github.com/tobiasschuerg/InfluxDB-Client-for-Arduino/pull/150) - `HTTPOptions::httpReadTimeout` is also set as the connect timeout for HTTP connection on ESP32. It also works for HTTPS connection since ESP32 Arduino SDK 2.0.0. 
  - [#156](https://github.com/tobiasschuerg/InfluxDB-Client-for-Arduino/pull/156) - Correctly rounding _writeBufferSize_, when _bufferSize/batchSize >= 256_. 
- - [#162](https://github.com/tobiasschuerg/InfluxDB-Client-for-Arduino/pull/162) - Fixed flushing of not full buffer after to timeout.
+ - [#162](https://github.com/tobiasschuerg/InfluxDB-Client-for-Arduino/pull/162) - Fixed flushing of not full buffer after the flush timeout.
 
 ## 3.8.0 [2021-04-01]
 ### Features