Update usage documentation for configuring authentication unattended (#173)

Related to #157

Author: HowardWolosky

GitHubConfiguration.ps1

@@ -836,13 +836,14 @@ function Set-GitHubAuthentication
         SecureString for use in future PowerShell sessions.
 
     .EXAMPLE
-        $secureString = ("<Your Access Token>" | ConvertTo-SecureString)
+        $secureString = ("<Your Access Token>" | ConvertTo-SecureString -AsPlainText -Force)
         $cred = New-Object System.Management.Automation.PSCredential "username is ignored", $secureString
         Set-GitHubAuthentication -Credential $cred
+        $secureString = $null # clear this out now that it's no longer needed
+        $cred = $null # clear this out now that it's no longer needed
 
-        Uses the API token stored in the password field of the provided credential object for
-        authentication, and stores it in a file on the machine as a SecureString for use in
-        future PowerShell sessions.
+        Allows you to specify your access token as a plain-text string ("<Your Access Token>")
+        which will be securely stored on the machine for use in all future PowerShell sessions.
 
     .EXAMPLE
         Set-GitHubAuthentication -SessionOnly

README.md

@@ -71,6 +71,14 @@ access token.
    securely cached to disk and will persist across all future PowerShell sessions.
 If you ever wish to clear it in the future, just call `Clear-GitHubAuthentication`).
 
+> For automated scenarios (like GithHub Actions) where you are dynamically getting the access token
+> needed for authentication, refer to `Example 2` in `Get-Help Set-StoreBrokerAuthentication -Examples`
+> for how to configure in a promptless fashion.
+>
+> Alternatively, you _could_ configure PowerShell itself to always pass in a plain-text access token
+> to any command (by setting `$PSDefaultParameterValues["*-GitHub*:AccessToken"] = "<access token>"`),
+> although keep in mind that this is insecure (any other process could access this plain-text value).
+
 A number of additional configuration options exist with this module, and they can be configured
 for just the current session or to persist across all future sessions with `Set-GitHubConfiguration`.
 For a full explanation of all possible configurations, run the following: