Fix/am snap diagram style and typo (#1132)

* Force line break in sequence diagram to prevent bad text wrapping

* Typo: pendind -> pending

snaps/concepts/keyring-api.md

@@ -135,7 +135,7 @@ User ->>+ Site: Create new account
 Site ->> Site: Custom logic to create account
 Site ->>+ Snap: keyring_createAccount(options)
 Snap ->> Snap: Custom logic to create account
-Snap ->>+ MetaMask: snap_manageAccounts("notify:accountCreated", account)
+Snap ->>+ MetaMask: snap_manageAccounts(<br/>"notify:accountCreated", account)
 User ->> MetaMask: Approve account creation
 MetaMask -->>- Snap: OK
 Snap -->>- Site: OK
@@ -190,7 +190,7 @@ User ->> MetaMask: Approve request
 
 MetaMask ->>+ Snap: keyring_submitRequest(request)
 Snap ->> Snap: Custom logic to handle request
-Snap -->>- MetaMask: { pendind: false, result }
+Snap -->>- MetaMask: { pending: false, result }
 
 MetaMask -->>- Dapp: result
 
@@ -250,7 +250,7 @@ Snap -->>- Site: request
 Site ->> Site: Custom logic to handle request
 Site ->>+ Snap: keyring_approveRequest(id, data?)
 Snap ->> Snap: Custom logic to handle request
-Snap ->>+ MetaMask: snap_manageAccounts("notify:requestApproved", { id, result })
+Snap ->>+ MetaMask: snap_manageAccounts(<br/>"notify:requestApproved", { id, result })
 
 MetaMask -->> Dapp: result
 MetaMask -->>- Snap: OK