[C++][Parquet] Add change log for the new release

[asfimport]

It will be helpful to document what changes went into each release. The idea is to write a brief summary of features added and important bugs fixed.

Reporter: Deepak Majeti / @majetideepak

Related issues:

• C++: Release 1.1.0 (blocks)

_{Note: This issue was originally created as PARQUET-985. Please see the migration documentation for further details.}

[asfimport]

Wes McKinney / @wesm:
We have https://github.com/apache/parquet-cpp/blob/master/CHANGELOG; perhaps we can write a brief summary in the CHANGELOG explaining the notable new features / improvements / bug fixes / changes.

[asfimport]

Deepak Majeti / @majetideepak:
Yeah! the JIRAs fixed can follow this summary.

[asfimport]

Wes McKinney / @wesm:
We should create a JIRA issue for each new release to write this summary; I guess we have to decide where to put it since the changelog has been automatically generated so far