📝 Update instructions to clone for a private repo, including updates (fastapi#1127)

Author: tiangolo

README.md

@@ -57,6 +57,74 @@ You can **just fork or clone** this repository and use it as is.
 
 ✨ It just works. ✨
 
+### How to Use a Private Repository
+
+If you want to have a private repository, GitHub won't allow you to simply fork it as it doesn't allow changing the visibility of forks.
+
+But you can do the following:
+
+- Create a new GitHub repo, for example `my-full-stack`.
+- Clone this repository manually, set the name with the name of the project you want to use, for example `my-full-stack`:
+
+```bash
+git clone [email protected]:tiangolo/full-stack-fastapi-template.git my-full-stack
+```
+
+- Enter into the new directory:
+
+```bash
+cd my-full-stack
+```
+
+- Set the new origin to your new repository, copy it from the GitHub interface, for example:
+
+```bash
+git remote set-url origin [email protected]:octocat/my-full-stack.git
+```
+
+- Add this repo as another "remote" to allow you to get updates later:
+
+```bash
+git remote add upstream [email protected]:tiangolo/full-stack-fastapi-template.git
+```
+
+- Push the code to your new repository:
+
+```bash
+git push -u origin master
+```
+
+### Update From the Original Template
+
+After cloning the repository, and after doing changes, you might want to get the latest changes from this original template.
+
+- Make sure you added the original repository as a remote, you can check it with:
+
+```bash
+git remote -v
+
+origin    [email protected]:octocat/my-full-stack.git (fetch)
+origin    [email protected]:octocat/my-full-stack.git (push)
+upstream    [email protected]:tiangolo/full-stack-fastapi-template.git (fetch)
+upstream    [email protected]:tiangolo/full-stack-fastapi-template.git (push)
+```
+
+- Pull the latest changes without merging:
+
+```bash
+git pull --no-commit upstream master
+```
+
+This will download the latest changes from this template without committing them, that way you can check everything is right before committing.
+
+- If there are conflicts, solve them in your editor.
+
+- Once you are done, commit the changes:
+
+```bash
+git merge --continue
+```
+
 ### Configure
 
 You can then update configs in the `.env` files to customize your configurations.