Auto-generate markdown command docs (#4451)

* Finish updating

* a couple improvements

* Update renames

* cleanup examples

docs/commands/dfr_to-csv.md

@@ -0,0 +1,30 @@
+---
+title: dfr to-csv
+layout: command
+version: 0.59.0
+---
+
+Saves dataframe to csv file
+
+## Signature
+
+```> dfr to-csv (file) --delimiter --no-header```
+
+## Parameters
+
+ -  `file`: file path to save dataframe
+ -  `--delimiter {string}`: file delimiter character
+ -  `--no-header`: Indicates if file doesn't have header
+
+## Examples
+
+Saves dataframe to csv file
+```shell
+> [[a b]; [1 2] [3 4]] | dfr to-df | dfr to-csv test.csv
+```
+
+Saves dataframe to csv file using other delimiter
+```shell
+> [[a b]; [1 2] [3 4]] | dfr to-df | dfr to-csv test.csv -d '|'
+```
+