Add precision to function as shared data type (#260)

Author: chenglou

pages/docs/manual/latest/function.mdx

@@ -8,7 +8,7 @@ canonical: "/docs/manual/latest/function"
 
 _Cheat sheet for the full function syntax at the end_.
 
-Functions are declared with an arrow and return an expression.
+ReScript functions are declared with an arrow and return an expression, just like JS functions. They compile to clean JS functions too.
 
 <CodeTab labels={["ReScript", "JS Output"]}>
 

pages/docs/manual/latest/shared-data-types.mdx

@@ -20,6 +20,7 @@ Unlike most compiled-to-js languages, in ReScript, **you don't need to write dat
 - Boolean.
 - Record. Record compiles to JS object. Therefore you can also treat JS objects as records. If they're too dynamic, consider modeling them on the ReScript side as a hashmap/dictionary [`Js.Dict`](api/js/dict) or a ReScript object.
 - Object. ReScript objects are JavaScript objects, vice-versa.
+- Function. They compile to clean JS functions.
 - Unit. The `unit` type, which has a single value `()`, compiles to `undefined` too. Likewise, you can treat an incoming JS `undefined` as `()`.
 
 <!-- TODO: talk about poly variant -->

pages/docs/manual/v8.0.0/function.mdx

@@ -8,7 +8,7 @@ canonical: "/docs/manual/latest/function"
 
 _Cheat sheet for the full function syntax at the end_.
 
-Functions are declared with an arrow and return an expression.
+ReScript functions are declared with an arrow and return an expression, just like JS functions. They compile to clean JS functions too.
 
 <CodeTab labels={["Reason (Old Syntax)", "ML (Older Syntax)", "JS Output"]}>
 

pages/docs/manual/v8.0.0/shared-data-types.mdx

@@ -20,6 +20,7 @@ Unlike most compiled-to-js languages, in ReScript, **you don't need to write dat
 - Boolean.
 - Record. Record compiles to JS object. Therefore you can also treat JS objects as records. If they're too dynamic, consider modeling them on the ReScript side as a hashmap/dictionary [`Js.Dict`](api/js/dict) or a ReScript object.
 - Object. ReScript objects are JavaScript objects, vice-versa.
+- Function. They compile to clean JS functions.
 - Unit. The `unit` type, which has a single value `()`, compiles to `undefined` too. Likewise, you can treat an incoming JS `undefined` as `()`.
 
 <!-- TODO: talk about poly variant -->