PARQUET-2121: Remove descriptions for the removed modules

[sekikn]

Make sure you have checked all steps below.

Jira

• My PR addresses the following Parquet Jira issues and references them in the PR title. For example, "PARQUET-1234: My Parquet PR"
  • https://issues.apache.org/jira/browse/PARQUET-2121
  • In case you are adding a dependency, check if the license complies with the ASF 3rd Party License Policy.

Tests

• My PR adds the following unit tests OR does not need testing for this extremely good reason:

No additional test since it's just a documentation fix.

Commits

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  1. Subject is separated from body by a blank line
  2. Subject is limited to 50 characters (not including Jira issue reference)
  3. Subject does not end with a period
  4. Subject uses the imperative mood ("add", not "adding")
  5. Body wraps at 72 characters
  6. Body explains "what" and "why", not "how"

Documentation

• In case of new functionality, my PR adds documentation that describes how to use it.
  • All the public functions and the classes in the PR contain Javadoc that explain what it does

[shangxinli]

Since the code is still there, do you think we can just add '(deprecated)' here?

[sekikn]

Thank you for the comment, @shangxinli! I updated the PR.
Instead of removing the lines, I just added '(deprecated)' to parquet-cascading* and parquet-scrooge in README.md, just like parquet-hive.

[shangxinli]

@sekikn Thanks for working on it! Just leave some minor comments.

[shangxinli]

Thanks for addressing the comments! There is one left over. After that, I think we can merge it.

[sekikn]

@shangxinli I'm afraid I can see just one comment at L69 of README.md...
Would you point to the comment left with a permalink or something? Maybe I don't understand GitHub's functionality or missed something.

[shangxinli]

The only comment left is in the .gitignore file. Question is should we remove 'parquet-scrooge/.cache'? If the code for parquet-scrooge is still there, there may be needed to keep it.

[sekikn]

Thank you for the elaboration, @shangxinli!
Let me confirm, I think the parquet-cascading* and parquet-scrooge directories were removed on the master branch in #888.
In addition, they had been renamed to "*-deprecated" before the removal, so the line in .gitignore in question has no effect.
So I'm not sure what "the code is still there" you mentioned means... Is my understanding correct?

[shangxinli]

Thank you for the elaboration, @shangxinli! Let me confirm, I think the parquet-cascading* and parquet-scrooge directories were removed on the master branch in #888. In addition, they had been renamed to "*-deprecated" before the removal, so the line in .gitignore in question has no effect. So I'm not sure what "the code is still there" you mentioned means... Is my understanding correct?

Thanks @sekikn for checking!