stdlib: move all imports to alpha.dagger.io

Signed-off-by: Solomon Hykes <solomon@dagger.io>

docs/learn/102-dev.md

@@ -136,7 +136,7 @@ Let's write the corresponding Cue code to a new file in our package:
 package multibucket
 
 import (
-    "dagger.io/dagger"
+    "alpha.dagger.io/dagger"
 )
 
 // Source code of the sample application
@@ -153,7 +153,7 @@ The second component of our plan is the Yarn package built from the app source c
 package multibucket
 
 import (
-    "dagger.io/js/yarn"
+    "alpha.dagger.io/js/yarn"
 )
 
 // Build the source code using Yarn
@@ -165,7 +165,7 @@ app: yarn.#Package & {
 Let's break it down:
 
 - `package multibucket`: this file is part of the multibucket package
-- `import ( "dagger.io/js/yarn" )`: import a package from the [Dagger Universe](../reference/universe/README.md).
+- `import ( "alpha.dagger.io/js/yarn" )`: import a package from the [Dagger Universe](../reference/universe/README.md).
 - `app: yarn.#Package`: apply the `#Package` definition at the key `app`
 - `&`: also merge the following values at the same key...
 - `{ source: src }`: set the key `app.source` to the value of `src`. This connects our 2 components, forming the first link in our DAG.
@@ -182,7 +182,7 @@ The third component of our plan is the Netlify site to which the app will be dep
 package multibucket
 
 import (
-    "dagger.io/netlify"
+    "alpha.dagger.io/netlify"
 )
 
 // Netlify site