replace content with submodule

.gitmodules

content

content/_index.en.md

content/_index.md

content/blog/_index.md

content/blog/example/index.md

content/docs/Set up/AdaptTetraDocToYou.md

content/docs/Set up/Getting-Started.md

content/docs/Set up/SetUrl.md

content/docs/Set up/_index.md

content/docs/Set up/img.png

content/docs/Set up/img_1.png

content/docs/Set up/img_2.png

content/docs/_index.md

content/privacy.md