Add support for Standards libs 3.1.1

[lolotoms]

Added to library-doc

• BuiltIn-3.1.1.json
• Collections-3.1.1.json
• DateTime-3.1.1.json
• Dialogs-3.1.1.json
• OperatingSystem-3.1.1.json
• Process-3.1.1.json
• Screenshot-3.1.1.json
• SeleniumLibrary-3.3.1.json
• String-3.1.1.json
• Telnet-3.1.1.json
• XML-3.1..json

[tomi]

Thank you for you contribution @lolotoms !