Remove FIXMEs now that released pack supports image extensions

Signed-off-by: Natalie Arellano <[email protected]>

Author: Natalie Arellano

content/docs/extension-author-guide/create-extension/setup-local-environment.md

@@ -38,17 +38,9 @@ Server: Docker Engine - Community
 
 `workspace=<your preferred workspace directory>`
 
-### Clone the pack repo and build it (FIXME: remove when pack with extensions-phase-2 support is released)
+### Ensure pack version supports image extensions
 
-`cd $workspace`
-
-`git clone [email protected]:buildpacks/pack.git`
-
-`cd pack`
-
-`git checkout extensions-phase-2-rc2`
-
-`make clean build`
+`pack version` - should be at least `0.28.0`
 
 ### Clone the samples repo
 
@@ -58,8 +50,6 @@ Server: Docker Engine - Community
 
 `cd samples`
 
-`git checkout extensions-phase-2` (FIXME: remove when `extensions-phase-2` merged)
-
 <!--+ if false +-->
 ---
 

content/docs/features/dockerfiles.md

@@ -118,7 +118,7 @@ For more information, consult the [migration guide](/docs/reference/spec/migrati
 
 Supported (phases 1 and 2):
 
-* [pack cli](https://github.com/buildpacks/pack) (version FIXME and above)
+* [pack cli](https://github.com/buildpacks/pack) (version `0.28.0` and above)
 
 Needs support:
 

content/docs/reference/spec/migration/platform-api-0.9-0.10.md

@@ -68,7 +68,7 @@ Platform 0.10 introduces image extensions as experimental components for customi
 
 Note: image extensions are not supported for Windows container images.
 
-* To create a builder with extensions, ensure the `pack` version in use is at least FIXME and enable experimental features: `pack config experimental`.
+* To create a builder with extensions, ensure the `pack` version in use is at least `0.28.0` and enable experimental features: `pack config experimental`.
 * Enable experimental features in the lifecycle by setting `CNB_EXPERIMENTAL_MODE=warn` or `CNB_EXPERIMENTAL_MODE=silent` in the lifecycle execution environment for ALL lifecycle phases
 * Invoke `analyzer` as usual
 * Invoke `detector` with a new optional argument: `-generated`, to specify the directory where Dockerfiles generated by image extensions will be output (defaults to `<layers>/generated`) and include image extensions in `order.toml`