Docs: enable packages reference docs for 7-beta (#23953)

* added packages reference menu item.

* removed the draft flag.

* Updated docs by running script.

docs/sources/packages_api/data/datemath/ismathstring.md

@@ -5,7 +5,6 @@
 title = "isMathString"
 keywords = ["grafana","documentation","sdk","@grafana/data"]
 type = "docs"
-draft = true
 +++
 
 ## dateMath.isMathString() function

docs/sources/packages_api/data/datemath/isvalid.md

@@ -5,7 +5,6 @@
 title = "isValid"
 keywords = ["grafana","documentation","sdk","@grafana/data"]
 type = "docs"
-draft = true
 +++
 
 ## dateMath.isValid() function

docs/sources/packages_api/data/datemath/parse.md

@@ -5,7 +5,6 @@
 title = "parse"
 keywords = ["grafana","documentation","sdk","@grafana/data"]
 type = "docs"
-draft = true
 +++
 
 ## dateMath.parse() function

docs/sources/packages_api/data/datemath/parsedatemath.md

@@ -5,7 +5,6 @@
 title = "parseDateMath"
 keywords = ["grafana","documentation","sdk","@grafana/data"]
 type = "docs"
-draft = true
 +++
 
 ## dateMath.parseDateMath() function