Create new Function read_it for reading data without heuristic detection

[bedantaguru]

Modify read_cells to optionally opt for "heuristic detection" and "structural assignment". The proposed function read_it (should be a wrapper for read_cells with appropriate arguments) can do the following things

• Read data as it is. Required for already structured data.
• Try to find out whether reading as it is is ok or not.
• Try to combine similar tables in a document based on headers.
• Try to alert the user about what else to be done in order to read the data from the selected file. If the file type is not supported or any additional package is required to inspect.
• Detect column type after (on-demand basis) (if skipped in read_it)
• Should support standard R objects too.

[bedantaguru]

read_it added but acts as a general-purpose reader. read_table added which is similar to what the issue is describing.
More improvement needed.