[docs] Adding help article for Legacy (#4390)

## Description

## Tests

docs/docs/.vitepress/sidebar.ts

@@ -39,6 +39,10 @@ export const sidebar = [
                         link: "/photos/features/free-up-space/",
                     },
                     { text: "Hidden photos", link: "/photos/features/hide" },
+                    {
+                        text: "Legacy",
+                        link: "/photos/features/legacy/",
+                    },
                     {
                         text: "Location tags",
                         link: "/photos/features/location-tags",

docs/docs/photos/features/legacy/index.md

@@ -0,0 +1,50 @@
+---
+title: Legacy
+description: Using Legacy to pass on your memories to loved ones
+---
+
+# Legacy
+
+Legacy allows trusted contacts to recover your account in your absence. The main usecase here is to pass on your memories after your death. It can also be useful for other cases - for e.g., when you forget your password and recovery key.
+
+Trusted Contacts can initiate a recovery, and if not blocked in 30 days, would be able to change the password to your account and thereby access your memories.
+
+## Adding a trusted contact
+
+You can add a trusted contact for your account using the mobile app for Ente Photos. Go to Settings -> Account -> Legacy, and click on "Add Trusted Contact". 
+
+You would be asked to enter the email address of the trusted contact you want to add or choose from a list of contacts on Ente. Please note that the trusted contact must be an Ente user.
+
+<div align="center">
+
+![Add Trusted Contact](add_trusted_contact.png){width=300px}
+
+</div>
+
+The trusted contact must accept your request. They can do so by going to Settings -> Account -> Legacy in the Ente Photos mobile app, and clicking on your email address within the Legacy accounts sections. Ente would also send an email notification to the trusted contact to nudge them to accept the invite.
+
+<div align="center">
+
+![Accept Trusted Contact Invite](accept_trusted_contact_invite.png){width=300px}
+
+</div>
+
+## Recovering an account as a trusted contact
+
+As a trusted contact, you can recover an account by going to Settings -> Account -> Legacy in the Ente photos app, tapping on the email address of the account within the Legacy account sections.
+
+<div align="center">
+
+![Initiate Account Recovery](initiate_account_recovery.png){width=300px}
+
+</div>
+
+Once the recovery is initiated, the account owner would get 30 days to block the recovery. After 30 days, you can go the same page in the app, where you will be prompted to change the password of the account. Once you change the password, you would be able to access the recovered account with the new password.
+
+## Blocking account recovery by a trusted contact
+
+After a trusted contact initiates a recover, you, as the account owner, would get 30 days to block the recovery. To do this, you must go to Settings -> Account -> Legacy, where you will see a message that recovery of the account has been initiated. Tapping on that will allow you to block the recovery.
+
+## Removing a trusted contact
+
+You can remove a trusted contact by going to Settings -> Account -> Legacy, tapping on the trusted contact you want to remove, and choosing "Remove" in the popup.