Ensure that the action is backwards-compatible (#25)

Bring 2 changes that ensure that the GitHub Action is backwards compatible:

- Append `http://` if the prefix is not provided in the `OP_CONNECT_HOST` (this is caused by the fact that `curl` guesses the protocol if not provided (https://linux.die.net/man/1/curl), which we missed when switching to using the 1Password CLI as the backend of the action)
- Set the default of export-env to true, since that was the default behavior of the action until we added the possibility to export secrets as step's output.

Also, the documentation is adjusted to reflect these changes.

README.md

@@ -43,6 +43,8 @@ jobs:
       - name: Load secret
         id: op-load-secret
         uses: 1password/load-secrets-action@v1
+        with:
+          export-env: false
         env:
           OP_CONNECT_HOST: <Your Connect instance URL>
           OP_CONNECT_TOKEN: ${{ secrets.OP_CONNECT_TOKEN }}
@@ -77,6 +79,8 @@ jobs:
       - name: Load Docker credentials
         id: load-docker-credentials
         uses: 1password/load-secrets-action@v1
+        with:
+          export-env: false
         env:
           OP_CONNECT_TOKEN: ${{ secrets.OP_CONNECT_TOKEN }}
           DOCKERHUB_USERNAME: op://app-cicd/docker/username
@@ -194,7 +198,7 @@ jobs:
 
 | Name             | Default | Description                                                                        |
 | ---------------- | ------- | ---------------------------------------------------------------------------------- |
-| `export-env`     | `false` | Export the loaded secrets as environment variables                                 |
+| `export-env`     | `true`  | Export the loaded secrets as environment variables                                 |
 | `unset-previous` | `false` | Whether to unset environment variables populated by 1Password in earlier job steps |
 
 ## Secrets Reference Syntax