Session key inline docs outdated

[juliangruber]

This is the old API:

synapse-sdk/packages/synapse-sdk/src/session/key.ts

Lines 11 to 21 in 3abd5c9

	* ```typescript
	* const sessionKey = synapse.createSessionkey(privateKey)
	* const expiries = await sessionKey.fetchExpiries([ADD_PIECES_TYPEHASH])
	* if (expiries[ADD_PIECES_TYPEHASH] * BigInt(1000) < BigInt(Date.now()) + HOUR_MILLIS) {
	* const DAY_MILLIS = BigInt(24) * HOUR_MILLIS
	* const loginTx = await sessionKey.login(BigInt(Date.now()) / BigInt(1000 + 30 * DAY_MILLIS), PDP_PERMISSIONS, "example.com")
	* const loginReceipt = await loginTx.wait()
	* }
	* synapse.setSession(sessionKey)
	* const context = await synapse.storage.createContext()
	* ```