Improved private template repository docs (#311)

* Improved private template repository docs

Signed-off-by: George <31376482+george-gca@users.noreply.github.com>

* Fixed missing link to `test_ssh_gitlab.yml`

Signed-off-by: George <31376482+george-gca@users.noreply.github.com>

* Making usage more clear

Signed-off-by: George <31376482+george-gca@users.noreply.github.com>

---------

Signed-off-by: George <31376482+george-gca@users.noreply.github.com>
Co-authored-by: andy Augustin <AndreasAugustin@users.noreply.github.com>

README.md

@@ -32,13 +32,15 @@ This GitHub action will help you to keep track of the template changes.
 * Ignore files and folders from syncing using a `.templatesyncignore` file
 * many configuration options
 * different lifecycle hooks are supported
-* different git provider. Default is GitHub, GitLab is also tested. See [.github/workflows/test_ssh_gitlab.yml] for an example.
+* different git provider. Default is GitHub, GitLab is also tested. See [.github/workflows/test_ssh_gitlab.yml](.github/workflows/test_ssh_gitlab.yml) for an example.
 
 ## Usage
 
+Usage changes depending on whether the template repository is public or private, regardless of the visibility of current repository.
+
 ### Public template repository
 
-Add this configuration to your github action
+Add this configuration to a github action in the current repository:
 
 ```yaml
 # File: .github/workflows/template-sync.yml
@@ -66,15 +68,15 @@ jobs:
           pr_labels: <label1>,<label2>[,...] # optional, no default
 ```
 
-You will receive a pull request within your repository if there are some changes available.
+You will receive a pull request within your repository if there are some changes available in the template.
 
 ### Private template repository
 
-If you have a private template repository.
+If your current repository was created from a private template, there are 2 possibilities.
 
-#### Using github app
+#### 1. Using github app
 
-You can create and use a [GitHub App][github-app] to handle the access to your private repository.
+You can create and use a [GitHub App][github-app] to handle the access to the private template repository.
 To generate a token for your app you can use a separate action like [tibdex/github-app-token][github-app-token].
 
 ```yaml
@@ -99,11 +101,11 @@ jobs:
           pr_labels: <label1>,<label2>[,...] # optional, no default
 ```
 
-#### SSH
+#### 2. SSH
 
 You have various options to use ssh keys with GitHub.
-An example are [deployment keys][deployment-keys]. For our use case write permissions are not needed.i
-Within the repository where the GitHub action is enabled add a secret (e.q. `SOURCE_REPO_SSH_PRIVATE_KEY`) with the content of your private SSH key.
+An example are [deployment keys][deployment-keys]. For our use case write permissions are not needed.
+Within the current repository, where the GitHub action is enabled, add a secret (e.q. `SOURCE_REPO_SSH_PRIVATE_KEY`) with the content of your private SSH key.
 Make sure that the read permissions of that secret fulfil your use case.
 Set the optional `source_repo_ssh_private_key` input parameter.
 It is also possible to use a different git provider, e.g. GitLab.