docs: Manual scenario for "Import account with private key" feature (#…

…26756)

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## **Description**

This PR documents the manual test scenario for the 'Import account with
private key' feature. Below is a summary of the validations included in
this manual scenario:

- Validate that the account selector is present at the top of the
wallet.
- Validate that the 'Add account or hardware wallet' option is available
at the bottom of the account selector list.
- Validate that the 'Import account' option is available in the next
menu.
- Validate that the user is directed to the Import page upon selecting
'Import account'.
- Validate that the user can paste their private key and click 'Import'.
- Validate that the newly imported account appears in the account
selector dropdown with an 'Imported' tag next to it.


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## **Related issues**

Fixes: #22006

## **Manual testing steps**

--> test/manual-scenarios/keyring/import account using private key.md
Rendered view of the manual scenario -
https://github.com/MetaMask/metamask-extension/blob/import-account-with-private-key-scenario/test/manual-scenarios/keyring/import%20account%20using%20private%20key.md

test/manual-scenarios/keyring/import account using private key.md

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+# Manual test scenario for the 'Import account with private key' feature
+
+Below is a summary of the validations included:-
+
+* Validate that the account selector is present at the top of the wallet.
+* Validate that the 'Add account or hardware wallet' option is available at the bottom of the account selector list.
+* Validate that the 'Import account' option is available in the next menu.
+* Validate that the user is directed to the Import page upon selecting 'Import account'.
+* Validate that the user can paste their private key and click 'Import'.
+* Validate that the newly imported account appears in the account selector dropdown with an 'Imported' tag next to it.
+
+```markdown
+
+# Feature: Import Account with Private Key
+
+In order to manage multiple accounts
+As a user of the wallet extension
+I want to import an account using a private key
+
+# Scenario: Accessing the 'Add account or hardware wallet' option
+
+Given I am on the wallet interface
+When I click the account selector at the top of my wallet
+Then I should see a list of accounts
+And I should see the 'Add account or hardware wallet' option at the bottom of the list
+
+# Scenario: Selecting the 'Import account' option
+
+Given I have clicked the account selector at the top of my wallet
+And I see the 'Add account or hardware wallet' option at the bottom of the list
+When I select 'Add account or hardware wallet'
+Then I should be directed to the next menu
+And I should see the 'Import account' option
+
+# Scenario: Importing an account with a private key
+
+Given I am on the import dialog modal
+When I see a field to paste my private key
+And I paste my private key (e.g.: 669456835741782c2ceca4e6ded60420ede38db2fb28742a1c9ae5ddf6680fa9) and click 'Import'
+Then I should see the newly imported account in the account selector dropdown
+And the newly imported account should have an 'Imported' tag next to it
+
+
+```