Support popular annotation formats

[letuananh]

Provide basic supports for popular annotation formats

• ELAN
• CoNLL
• Audacity
• PENN treebank
• Pratt

[vicchuayh]

for consideration: CHAT format

e.g., https://sla.talkbank.org/TBB/childes/Eng-NA/Bates/Free20/amy.cha

[letuananh]

Documentation for CHAT format: https://talkbank.org/manuals/CHAT.pdf