PLDoc- Add release information

[maven-release-plugin] copy for tag pldoc-1.5.16

[maven-release-plugin] copy for tag pldoc-1.5.15

[maven-release-plugin] copy for tag pldoc-1.5.14

[maven-release-plugin] copy for tag pldoc-1.5.13

[maven-release-plugin] copy for tag pldoc-1.5.12

Add release 1.5.11 change information

Add release 1.5.11 change information

[maven-release-plugin] copy for tag pldoc-1.5.9

[maven-release-plugin] copy for tag pldoc-1.5.8