bring docs for use of directives up to date

mage/magefile_tmpl.go

@@ -1,6 +1,7 @@
 package mage
 
-var mageTpl = `// +build mage
+var mageTpl = `//go:build mage
+// +build mage
 
 package main
 

mage/testdata/mageimport/magefile.go

@@ -12,9 +12,9 @@ package main
 import (
 	"fmt"
 
-	// mage:import
+	//mage:import
 	_ "github.com/magefile/mage/mage/testdata/mageimport/subdir1"
-	// mage:import zz
+	//mage:import zz
 	"github.com/magefile/mage/mage/testdata/mageimport/subdir2"
 )
 

mage/testdata/mageimport/oneline/magefile.go

@@ -2,5 +2,5 @@
 
 package main
 
-// mage:import
+//mage:import
 import _ "github.com/magefile/mage/mage/testdata/mageimport/oneline/other"

mage/testdata/mageimport/tagged/magefile.go

@@ -3,6 +3,6 @@
 package main
 
 import (
-	// mage:import
+	//mage:import
 	_ "github.com/magefile/mage/mage/testdata/mageimport/tagged/pkg"
 )

parse/testdata/importself/magefile.go

@@ -5,10 +5,10 @@ package main
 import (
 	"fmt"
 
-	// mage:import
+	//mage:import
 	_ "github.com/magefile/mage/parse/testdata/importself"
 )
 
-func Build(){
+func Build() {
 	fmt.Println("built")
-}
+}

site/content/howitworks/_index.en.md

@@ -4,7 +4,7 @@ weight = 50
 +++
 
 Mage scans the current directory for go files with the `mage` build tag (i.e.
-`// +build mage`), using the normal go build rules for following build
+`//go:build mage`), using the normal go build rules for following build
 constraints (aside from requiring the mage tag).  It then parses those files to
 find the build targets, generates a main file for the command, and compiles a
 binary from those files.  The magefiles are hashed so that if they remain

site/content/importing/_index.en.md

@@ -16,7 +16,7 @@ let you import a main package.
 
 In addition, all package files will be imported, so long as they don't have a 
 build tag.  If you try to import a package consisting only of files with build 
-tags (e.g. `//+build mage`), it will cause an error since mage doesn't set any 
+tags (e.g. `//go:build mage`), it will cause an error since mage doesn't set any 
 build tags when importing packages.  Any exported function, in imported 
 packages, that matches Mage's allowed formats will be picked up as a target.
 
@@ -27,15 +27,15 @@ like a normal magefile.
 
 ## Two Ways to Import
 
-Importing targets from a package simply requires adding a `// mage:import`
+Importing targets from a package simply requires adding a `//mage:import`
 comment on an import statement in your magefile.  If there is a name after this
 tag, the targets will be imported into what is effectively like a namespace.
 
 ```go
 import (
-    // mage:import
+    //mage:import
     _ "example.com/me/foobar" 
-    // mage:import build
+    //mage:import build
     "example.com/me/builder"
 )
 ```

site/content/index.md

@@ -70,7 +70,7 @@ asdf global mage latest
 ## Example Magefile
 
 ```go
-//+build mage
+//go:build mage
 
 package main
 

site/content/magefiles/_index.en.md

@@ -8,7 +8,7 @@ A mage file is any regular go file marked with a build target of "mage" and in
 package main.
 
 ```go
-// +build mage
+//go:build mage
 
 package main
 ```
@@ -25,7 +25,7 @@ use any of Go's usual build constraints, so you can include and exclude
 magefiles based on OS, arch, etc, whether in the filename or in the +build line.
 
 ```go
-// +build mage
+//go:build mage
 
 // A comment on the package will be output when you list the targets of a
 // magefile.

site/content/zeroInstall/_index.en.md

@@ -8,7 +8,7 @@ Don't want to depend on another binary in your environment?  You can run
 mage directly out of your vendor directory (or GOPATH) with `go run`.
 
 Just save a file like this (I'll call it `mage.go`, but it can be named
-anything) and note that the build tag is *not* `+build mage`. Mage will
+anything) and note that the build tag is *not* `go:build mage`. Mage will
 create its own main file, so we need this one to be excluded
 from when your magefiles are compiled.