Update 'Checking Out the Code' section
Update 'Checking Out the Code' section

Branch names corrected.
artspb/intellij-sdk-docs,artspb/intellij-sdk-docs,artspb/intellij-sdk-docs,JetBrains/intellij-sdk-docs,JetBrains/intellij-sdk-docs,artspb/intellij-sdk-docs,JetBrains/intellij-sdk-docs