doc : Add steps to remove CRC pull secret from OS provided tools (#2572)

Add steps for Windows, Linux (GNOME) and MacOS to instruct user on how
to remove the CRC pull secret from credential managers on abovementioned
Operating Systems.

Signed-off-by: Rohan Kumar <[email protected]>

Author: rohanKanojia

modules/ROOT/pages/using.adoc

@@ -23,6 +23,50 @@ Only one preset can be active at a time.
 * xref:installing.adoc#minimum-system-requirements[Minimum system requirements].
 * xref:configuring.adoc#changing-the-selected-preset[Changing the selected preset].
 
+[id='about-pullsecrets']
+== About Pull Secrets
+While starting cluster configured with {openshift} or {ushift} preset, {prod} would request you to provide a pull secret. It's required to pull some {ocp} specific container images.
+You need to download it from the Pull Secret section of the link:https://console.redhat.com/openshift/create/local[{prod} page on the {rh} Hybrid Cloud Console].
+
+Once you provide this pull secret, it gets stored in Operating System's credential manager so that {prod} doesn't ask for pull secret again in case you delete existing cluster and create
+a new one.
+
+Please note that this pull secret would only be removed from the Operating System's credential manager when user runs [command]`{bin} cleanup` command.
+
+If you manually want to remove/update pull secret from your Operating System's credential manager configuration.
+
+[id='clearning-credential-manager-pullsecret']
+=== Clearing Pull Secret from Credential Manager
+Steps to clear entries from the Credential Manager on different operating systems.
+
+==== Windows
+
+1. Open the Control Panel.
+2. Go to `User Accounts` > `Credential Manager`.
+3. Choose `Windows Credentials`.
+4. Find the {prod} pull secret entry you want to delete.
+5. Click on the entry to expand it.
+6. Click `Remove` to delete the credential.
+
+==== Linux
+
+For Linux, we assume you're using https://wiki.gnome.org/Projects/GnomeKeyring[GNOME Keyring]:
+
+1. Open the `Activities` overview and start typing `Passwords`.
+2. Click on `Passwords and Keys` to open https://wiki.gnome.org/Projects/GnomeKeyring[GNOME Keyring].
+3. Click on `Login` entry under `Passwords`
+4. Find the {prod} pull secret entry you want to delete.
+5. Right-click the entry you want to delete.
+6. Select `Delete` and confirm the deletion.
+
+==== MacOS
+
+1. Open `Keychain Access` from the `Applications` > `Utilities` folder.
+2. Select the keychain where the credential is stored (e.g., `login`, `iCloud`).
+3. Find the {prod} pull secret entry you want to delete.
+4. Right-click the entry and select `Delete`.
+5. Confirm the deletion when prompted.
+
 [id='setting-up']
 == Setting up {prod}