update .gitignore

Author: jrdegreeff

.gitignore

@@ -5,7 +5,8 @@
 Manifest.toml
 
 # generated docs
-docs/build
+docs/build/
+docs/src/generated/
 
 # dftk artifacts
 dftk.json
@@ -14,4 +15,4 @@ dftk.checkpoint.jld2
 dftk.scfres.jld2
 
 # Directory used for storing artifacts from examples
-artifacts/
+artifacts/