Revert "Update generate-all-docs.yml (Azure#17270)" (Azure#17306)

This reverts commit 447e6f7.

Author: msyyc

eng/pipelines/generate-all-docs.yml

@@ -9,7 +9,7 @@ jobs:
     variables:
       skipComponentGovernanceDetection: true
 
-    timeoutInMinutes: 1200
+    timeoutInMinutes: 120
 
     pool:
       vmImage: 'ubuntu-18.04'
@@ -35,4 +35,4 @@ jobs:
       - task: PublishPipelineArtifact@0
         inputs:
           artifactName: 'documentation' 
-          targetPath: '$(Build.SourcesDirectory)/_docs'
+          targetPath: '$(Build.SourcesDirectory)/_docs'