parsecsv: Updated documentation (#10330)

[jiro4989]

Updated documentation for parsecsv module.

• See also links
• Runnable examples

ref #10330

[narimiran]

It would be nice if the example would also show (a part of) the output, so it is more clear what does it do.

So for this example, that would be:

new row: 
##One:1##
##Two:2##
##Three:3##
##Four:4##
new row: 
##One:10##
...

But I would change ## to something else (or nothing at all: echo col, ": ", p.rowEntry(col)), so that you don't have to write the output in the documentation like ## # ##One:1##, but just: ## # One: 1

[narimiran]

I cannot comment on the line 59, as you didn't change it so I'm doing it here:

Make the first letter of the sentence an uppercase. Also try to think if you can describe CsvParser in a bit more detail (maybe put the descriptions for row and headers as a part of CsvParser documentation. Something like this:

type
  CsvRow* = seq[string] ## A row in a CSV file.
  CsvParser* = object of BaseLexer ## The parser object.
    ##
    ## It consists of two public fields:
    ## * `row` is the current row
    ## * `headers` are the columns that are defined in the csv file
    ##   (read using `readHeaderRow <#readHeaderRow,CsvParser>`_).
    ##   Used with `rowEntry <#rowEntry,CsvParser,string>`_).
    row*: CsvRow
    filename: string
    sep, quote, esc: char
    skipWhite: bool
    currRow: int
    headers*: seq[string]
  CsvError* = object of IOError ## An exception that is raised if
                                ## a parsing error occurs.

[narimiran]

Also, on the line 59 (at the end of top-level documentation) I would add "See also" section, linking to similar modules:

(...)
##       echo "##", col, ":", p.rowEntry(col), "##"
##   p.close()
##
##
## See also
## ========
##
## * `parseopt module <#parseopt.html>`_
## * `parsecfg module <#parsecfg.html>`_
## * `parsexml module <#parsexml.html>`_
## * `parsesql module <#parsesql.html>`_

Since streams is frequently used in the examples, it should be linked here too. Maybe some other module too.