[Canvas][Docs] Updates Canvas function reference

docs/canvas/canvas-client-functions.asciidoc

@@ -9,71 +9,171 @@ or interact with the workpad to read filters.
 
 A *** denotes a required argument.
 
+A *†* denotes an argument can be passed multiple times.
+
 [float]
-=== asset
+[[asset_fn]]
+=== `asset`
 
 Uses Canvas workpad asset objects to provide argument values. Usually images.
 
-*Accepts:* null
+*Accepts:* `null`
 
 [cols="3*^<"]
 |===
 |Argument |Type |Description
 
-|_Unnamed_*
-|string
+|_Unnamed_ ***
+|`string`
 |The ID of the asset value to return
 |===
 
-*Returns:* string
+*Returns:* `string`
 
 
 [float]
-=== browser
+[[filters_fn]]
+=== `filters`
 
-Forces the interpreter to return to the browser.
+Collects element filters on the workpad, usually to provide them to a data source.
 
-*Accepts:* Anything or nothing
+*Accepts:* `null`
 
-*Returns:* Depends on your input and arguments
+*Returns:* `filter`
 
 [float]
-=== filters
+[[location_fn]]
+=== `location`
 
-Collects element filters on the workpad, usually to provide them to a data source.
+Uses the browser's location functionality to get your current location. Usually 
+quite slow, but fairly accurate.
 
-*Accepts:* null
+*Accepts:* `null`
 
-*Returns:* filter
+*Returns:* `datatable`
 
 [float]
-=== location
+[[markdown_fn]]
+=== `markdown`
 
-Uses the browser's location functionality to get your current location. Usually 
-quite slow, but fairly accurate.
+Adds an element for rendering Markdown text. Great for single numbers, metrics, or paragraphs of text.
+
+*Accepts:* `datatable`, `null`
+
+[cols="3*^<"]
+|===
+|Argument |Type |Description
+
+|_Unnamed_ *†*
 
-*Accepts:* null
+Alias: `expression`, `content`
+|`string`
+|A `string` containing Markdown. You can pass this multiple 
+times to achieve concatenation 
 
-*Returns:* datatable
+Default: `""`
+
+|`font`
+|`style`
+|Font settings. Technically, you can put other styles in here too 
+
+Default: `{<<font_fn>>}`
+|===
+
+*Returns:* `render`
 
 [float]
-=== urlparam
+[[timelion_fn]]
+=== `timelion`
 
-Accesses URL parameters and use them in expressions. This will always return a string.
+Uses Timelion to extract one or more time series from many sources.
 
-*Accepts:* null
+*Accepts:* `filter`
 
 [cols="3*^<"]
 |===
 |Argument |Type |Description
 
-|_Unnamed_*  (Aliases: `var`, `variable`)
-|string
+|_Unnamed_ 
+
+Aliases: `q`, `query` 
+|`string`
+|A Timelion query 
+
+Default: `".es(*)"`
+
+|`interval`
+|`string`
+|Bucket interval for the time series 
+
+Default: `"auto"`
+
+|`from`
+|`string`
+|{es} `datemath` string for the start of the time range 
+
+Default: `"now-1y"`
+
+|`to`
+|`string`
+|{es} date math `string` for the end of the time range 
+
+Default: `"now"`
+
+|`timezone`
+|`string`
+|Time zone for the time range 
+
+Default: `"UTC"`
+|===
+
+*Returns:* `datatable`
+
+[float]
+[[to_fn]]
+=== `to`
+
+Explicitly casts from one type to another.
+
+*Accepts:* `any`
+
+[cols="3*^<"]
+|===
+|Argument |Type |Description
+
+|_Unnamed_ *** 
+
+Alias: `type`
+|`string`
+|A known type
+|===
+
+*Returns:* Depends on your input and arguments
+
+[float]
+[[urlparam_fn]]
+=== `urlparam`
+
+Accesses URL parameters and use them in expressions. This will always return a `string`.
+
+*Accepts:* `null`
+
+[cols="3*^<"]
+|===
+|Argument |Type |Description
+
+|_Unnamed_ ***  
+
+Aliases: `var`, `variable`
+|`string`
 |The URL hash parameter to access
 
-|default
-|string
-|Return this string if the url parameter is not defined  (default: `""`)
+|`default`
+|`string`
+|Return this `string` if the url parameter is not defined  
+
+Default: `""`
 |===
 
-*Returns:* string
+*Returns:* `string`
+