docs(viewer): the Markdown and PDF report download options

The Download list stopped at TSQL DDL, but the modal has offered Markdown
for a while and now offers a server-side PDF report as well (dc/dc#432).

The PDF report is the typeset one: SAS formats and labels applied,
landscape, headers repeated per page, and a footer carrying the filter,
user, timestamp and page number, capped at 2000 rows with the cap stated
when it is reached.

docs/dcu-tableviewer.md

@@ -47,6 +47,10 @@ The Download button gives several options for obtaining the current view of data
 
 5) TSQL DDL.  A DDL download using SQL Server flavoured syntax.
 
+6) Markdown.  A pipe delimited markdown table, ready to paste into a wiki or a ticket.
+
+7) PDF report.  A report typeset by SAS: landscape A4, the dataset name as the title, the column headers repeated on every page, and a footer on every page carrying the filter, the user, the timestamp and the page number.  SAS formats and labels are applied, so this shows formatted values rather than the stored values the grid displays.  It is capped at the first 2,000 rows, and the footer says so when the cap is reached.
+
 Note - if the table is registered in Data Controller as being TXTEMPORAL (SCD2) then the download option will prefilter for the _current_ records and removes the valid from / valid to variables.  This makes the CSV suitable for DC file upload, if desired.
 
 Note that all the above items are exported from backend.  There is also a _frontend_ context menu that can be used in the VIEW screen (right click menu) for quick export into CSV or Excel formats.   

docs/visual-analytics.md

@@ -73,7 +73,7 @@ Repeat the parameter to add mappings.  A report with two tabs, each holding its
 | Tab 1 | `...?embed=va&va_parmap=REGION_TAB1-REGION` |
 | Tab 2 | `...?embed=va&va_parmap=REGION_TAB2-REGION` |
 
-The applied filter is visible in the editor, above the grid - here the parameter `DROPDOWN_TAB1` filtering `SOME_DROPDOWN`, which is not its name:
+The applied filter is visible in the editor, above the grid - here the parameter `DROPDOWN_TAB1` filtering `SOME_DROPDOWN`, which is not its name (the date parameter beside it is name-matched, which is the default):
 
 ![A va_parmap mapping filtering a column](img/va-parmap-filtered.png)
 
@@ -120,11 +120,7 @@ A mapping can resolve the parameter value through a **named date anchor** before
 https://yourserver/DC/#/editor/<library>/<table>?embed=va&va_parmap=SELECTED_DATE-D_DATE:ADD(QUARTER_START,-1)
 ```
 
-A report that sends `SELECTED_DATE = 27FEB1961` then filters `D_DATE` on 1961-02-27 **and** 1960-10-01 - the selected date, plus the same point one quarter earlier:
+A report that sends `SELECTED_DATE = 27FEB1961` then filters `D_DATE` on 1961-02-27 **and** 1960-10-01 - the selected date, plus the same point one quarter earlier.
-
-In the screenshot below the mapping is `SELECTED_DATE-SOME_DATE:ADD(QUARTER_START,-1)` against the demo table, and the parameter sends 27FEB1961:
-
-![A date anchor applied to the filter](img/va-parmap-transform.png)
 
 The clause carries both values, so the row for the selected date and the row for the previous quarter are both included.