Revert "Add Hello World post"

This reverts commit 2e70de7828c5e1de3b307405d66289206cca5cfd.
Revert "Update image"

This reverts commit d1d2ddb8297cfff5b4826b7b4117a4e7c19f7888.
Revert "Update some categories"

This reverts commit f8fd92085334f2cf7956287f2a06c69b1d3ae7ee.
Revert "Remove test posts"

This reverts commit b1f6757c62fcc822c18953ec8c8b28daec703253.