Initial commit
Add composer json.
Add seo metadata model.
Add seo page class.
Update README.md
Improve seo metadata model.
Add seo metadata form type.
Add 'src/Silvestra/Component/Seo/' from commit '8134768b374650c65a0c7a0773ca18b21386b856'

git-subtree-dir: src/Silvestra/Component/Seo
git-subtree-mainline: 673e3627aad561568d31b87a420c4291b956a348
git-subtree-split: 8134768b374650c65a0c7a0773ca18b21386b856