Add support for PostgreSQL v15.1

Add support for PostgreSQL v15.1 (#3)

* Update PostgreSQL version to 15.1

* Remove unnecessary Docker image build argument

* Remove unnecessary lines

* Fix error: 'Empty continuation line'

* Use 7-Zip to bypass long path related issue

* Use 7-Zip to unzip PostgreSQL archive

* Use the same types of quotes and path separator

* Fix command used for downloading archive

* Enable long paths support

Add support for PostgreSQL v14.0

Fix path pointing to posgresql/README.md file (#2)

* Fix path to README.md file

* Fix path, take 2