Minor fix to docs for read_csv

[tnixon]

Fixed documentation of the escapechar parameter of read_csv function
(docs incorrectly say this is for escaping the delimiter - it is for escaping a quotechar)

[codecov-commenter]

Codecov Report

Merging #2205 (838c5f1) into master (07d8462) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2205   +/-   ##
=======================================
  Coverage   95.31%   95.31%           
=======================================
  Files          60       60           
  Lines       13746    13746           
=======================================
  Hits        13102    13102           
  Misses        644      644           

Impacted Files	Coverage Δ
databricks/koalas/namespace.py	84.75% <ø> (ø)

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[HyukjinKwon]

Thanks, @tnixon. This library has been merged into Apache Spark: https://github.com/apache/spark. Would you mind proposing the PR there?

[tnixon]

Yes, I can do that.