Add imports docpage

Author: odersky

docs/docs/reference/changed-features/imports.md

@@ -0,0 +1,59 @@
+---
+layout: doc-page
+title: "Imports"
+---
+
+The syntax of wildcard and renaming imports (and exports) has changed.
+
+## Wildcard Imports
+
+Wildcard imports are now expressed with `*` instead of underscore. Example:
+```scala
+import scala.annotation.*  // imports everything in the annotation package
+```
+
+If you want to import a member named `*` specifically, you can use backticks around it.
+
+```scala
+object A:
+   def * = ...
+   def min = ...
+
+object B:
+  import A.`*`   // imports just `*`
+
+object C:
+  import A.*     // imports everything in A
+```
+
+## Renaming Imports
+
+To rename or exclude an import, we now use `as` instead of `=>`. A single renaming import no longer needs to be enclosed in braces. Examples:
+
+```scala
+import A.{min as minimum, `*` as multiply}
+import Predef.{augmentString as _, *}     // imports everything except augmentString
+import scala.annotation as ann
+import java as j
+```
+
+### Migration
+
+To support cross-building, Scala 3.0 supports the old import syntax with `_` for wildcards and `=>` for renamings in addition to the new one. The old syntax
+will be dropped in a future versions. Automatic rewritings from old to new syntax
+are offered under settings `-source 3.1-migration -rewrite`.
+
+### Syntax
+
+```
+Import            ::=  ‘import’ ImportExpr {‘,’ ImportExpr}
+Export            ::=  ‘export’ ImportExpr {‘,’ ImportExpr}
+ImportExpr        ::=  SimpleRef {‘.’ id} ‘.’ ImportSpec
+ImportSpec        ::=  NamedSelector
+                    |  WildcardSelector
+                    | ‘{’ ImportSelectors) ‘}’
+NamedSelector     ::=  id [‘as’ (id | ‘_’)]
+WildCardSelector  ::=  ‘*' | ‘given’ [InfixType]
+ImportSelectors   ::=  NamedSelector [‘,’ ImportSelectors]
+                    |  WildCardSelector {‘,’ WildCardSelector}
+```

docs/docs/reference/changed-features/main-functions.md

@@ -62,7 +62,7 @@ For instance, the `happyBirthDay` method above would generate additional code eq
 
 ```scala
 final class happyBirthday:
-   import scala.util.CommandLineParser => CLP
+   import scala.util.CommandLineParser as CLP
    <static> def main(args: Array[String]): Unit =
       try
          happyBirthday(

docs/sidebar.yml

@@ -115,8 +115,6 @@ sidebar:
               url: docs/reference/other-new-features/control-syntax.html
             - title: Optional Braces
               url: docs/reference/other-new-features/indentation.html
-            - title: Imports
-              url: docs/reference/other-new-features/imports.html
             - title: Explicit Nulls
               url: docs/reference/other-new-features/explicit-nulls.html
             - title: Safe Initialization
@@ -131,6 +129,8 @@ sidebar:
               url: docs/reference/changed-features/operators.html
             - title: Wildcard Types
               url: docs/reference/changed-features/wildcards.html
+            - title: Imports
+              url: docs/reference/changed-features/imports.html
             - title: Type Checking
               url: docs/reference/changed-features/type-checking.html
             - title: Type Inference