documentation of statgl_fetch insufficient

[AlexanderKrabbe]

We should update the documentation of the behavior of the function statgl_fetch().

When using statgl_fetch the retrived data is as standard shown with the text and not the code string. Can be changed with .col_code = TRUE

However, this is not easily read from the documentation and can lead to unhelpfull warnings and errors if the text string is used as the code variable.

Example:
> statgl_fetch(statgl_url("ARXLED1")) 
print(df) 
 time  month     value
   <chr> <chr>     <int>
 1 1989  January      NA
 2 1989  February     NA
..., ..., ..., ...

> statgl_fetch(statgl_url("ARXLED1"), month = px_all(), time= c("2022")) 
lexical error: invalid char in json text.
                                       Bad Request
                     (right here) ------^

> statgl_meta("ARXLED1")
$title
[1] "Registered jobseekers by time, district, place of residence and month"

$url
[1] "https://bank.stat.gl:443/api/v1/en/Greenland/AR/AR20/ARXLED1.px"

$variables
# A tibble: 4 x 6
  code   text               elimination time  values     valueTexts
  <chr>  <chr>              <lgl>       <lgl> <list>     <list>    
1 aar    time               NA          TRUE  <chr [36]> <chr [36]>
2 dist_k district           TRUE        NA    <chr [18]> <chr [18]>
3 md     month              NA          NA    <chr [13]> <chr [13]>
4 type_k place of residence TRUE        NA    <chr [3]>  <chr [3]> 

it is now easy to see, that the that the code to retrive the columns are different than the text displayed.

> statgl_fetch(statgl_url("ARXLED1"), md = px_all(), aar = 2022) 
# A tibble: 13 x 3
   time  month            value
   <chr> <chr>            <int>
 1 2022  January           1907
 2 2022  February          1830
 3 2022  March             1857
 4 2022  April             1551
 5 2022  May               1458
 6 2022  June              1210
 7 2022  July              1143
 8 2022  August            1121
 9 2022  September          987
10 2022  October           1063
11 2022  November          1223
12 2022  December          1432
13 2022  Average per year  1399