Merge ~ogayot/curtin:curtin-stages-doc into curtin:master

[Olivier Gayot]

doc: remove duplicate section about extract subcommand

doc: remove duplicate section about extract subcommand

[Server Team CI bot (server-team-bot)]

PASSED: Continuous integration, rev:cae3769da9da6c52c8b942a5122e166394e3ffac
https://jenkins.canonical.com/server-team/job/curtin-ci/15/
Executed test runs:
    SUCCESS: https://jenkins.canonical.com/server-team/job/curtin-ci/nodes=metal-amd64/15/
    SUCCESS: https://jenkins.canonical.com/server-team/job/curtin-ci/nodes=metal-ppc64el/15/
    SUCCESS: https://jenkins.canonical.com/server-team/job/curtin-ci/nodes=metal-s390x/15/

Click here to trigger a rebuild:
https://jenkins.canonical.com/server-team/job/curtin-ci/15//rebuild

review: Approve (continuous-integration)

[Dan Bungert (dbungert)]

review: Approve

diff --git a/doc/topics/config.rst b/doc/topics/config.rst
index ec8a109..ff766c7 100644
--- a/doc/topics/config.rst
+++ b/doc/topics/config.rst
@@ -706,7 +706,7 @@ This results in Curtin downloading the following URLs::
 stages
 ~~~~~~
 Curtin installation executes in stages.  At each stage, Curtin will look for
-a list of commands to run at each stage by reading in from the Curtin config
+a list of commands to run by reading in from the Curtin config
 *<stage_name>_commands* which is a dictionary and each key contains a list
 of commands to run.  Users may override the stages value to control
 what curtin stages execute.  During each stage, the commands are executed
@@ -733,10 +733,6 @@ This stage runs ``curtin net-meta auto`` by default.
 
 This stage runs ``curtin extract`` by default.
 
-- **extract**: *Writing install sources to disk*
-
-This stage runs ``curtin extract`` by default.
-
 - **curthooks**: *Configuring installed system*
 
 This stage runs ``curtin curthooks`` by default.