TFJS doc parser: some commands are missing scope

[vvmnnnkv]

Description

Noticed issue in tfjs parsed .json file:
e.g. if you see tf.GraphModel in tfjs API, it's methods are listed w/o tf.GraphModel. prefix.
Doc parser doesn't add tf.GraphModel prefix, so all these methods appear as is they were in global scope.

How to Reproduce

See tf.Tensor, tf.GraphModel, etc. in API doc https://js.tensorflow.org/api/latest/#class:GraphModel
Check docs-crawler/docs/output/tfjs/1.5.1.json, notice all methods are in global scope.

Expected Behavior

Parsed data should contain indication of class where method belongs.
(Or just skip all these methods because they are not under tf. but rather in specific classes, which requires target support anyway?)

Screenshots

n/a

System Information

• OS: [e.g. iOS]
• OS Version: [e.g. 22]
• Language Version: [e.g. Python 3.7, Node 10.18.1]
• Package Manager Version: [e.g. Conda 4.6.1, NPM 6.14.1]
• Browser (if applicable): [e.g. Google Chrome]
• Browser Version (if applicable): [e.g. 81.0.4044.138]

Additional Context

Might be related to #16