doc(e2e): add env var selection doc for different networks

Author: Ansonhkg

packages/e2e/README.md

@@ -29,6 +29,9 @@ LIT_YELLOWSTONE_PRIVATE_RPC_URL=http://127.0.0.1:8545
 LIT_MAINNET_RPC_URL=https://mainnet-rpc.example
 ```
 
+See env var selection activity diagram
+![](https://www.plantuml.com/plantuml/png/ZPHlRzis4CRVwrFSzCe6ycSTLcombwoQ9sn1LJbGP7T3CGYiT8a9KwH0KagCeY_tBVRfzab6KH9hsN6N131iukwvttDtk3TA4wdhaddVw0sM21KZb7kUVVPc2P82uZ1zlqpU0l866YBd7hs7oV1OymBlASS2X3G_L5rLGceiVfw24UGmsQ6QUW0plP7Y4K8fJPn_80bK0HSQ5EfMneduSvEfjAWyP0fXmiNKGrxGUy-R_OeQPMagMn6LYye4C94J1eq2HXkSZabpmRNnfi2tKVuHuKeXT08QbGwDAd8jTot3h9Aq8HhVuWwk85ekWYXx5zobOP85YyLo5QTpXpXeMOR_bRfPXyTArgA5tmikgLAKFtoziVXKOQwnW98eZH98dekQQzZYxdGpHsswkWAVamTotdNfi9fzNGYkyKdV4hqn7kBWjo3hUh9OncduHvhT1kdlRRbM-2ZZX953AoTaXqMnTdf30FlDjwOSQrBbAydSr9BRHRPAeX5S7tAQYua7y4Vv0yKSpFgJcccJ25h0g-z-kFZM_B-Q_VZw-zUMqU78WMI_g923GjI_7cnI9CIsha0qA2Kj4BPkRonB6A-pTP3SVU2e7uNS_ZKuwty3vV39phF0vWpijtOdFn-xF2gHPd-6KRHyVvSkup2xJMxMGHgw3dP9FJoOLvEpqRfIiylB7J8c7fKM7C-DxGj6TIM55hbW5xaeB-Vzo9udjQ4TwyimtmKtiTdV5w4PbFDyGoZ_AjYpfTojUxQ06PW6KbMCvkGZm-cNsVSJ6QdX4rLQdTgrnGRpRRjIGuwxb3-Pv6ku5-PRtxThlyTfxutRTkCgHwKkJDw7GSHS4RiU7SvUk49zJ3BQM1ThyntdIXb8wz-1JYpXz5b4jzWZaLYC5HfAEfjpgAt-HxB5ufnow1jkQkor_dfgrSV0RbGmAKLHCuH7ofZHGnZdsjH-JWU03i-XZKtDePSsgkf5a7sTxjFypNwfAIj0ech3FlN2P_3bwfz1P-aC3i_evxatYmnVITGMdSR4__UVlo7a3Qo9LBwnPm_a6rEoBjb_)
+
 Make sure the referenced network (local Naga cluster, Shiva-managed testnet, or live subnet) is running and reachable from your test machine.
 
 > Heads up: when targeting `naga-proto` or `naga`, the helpers only fund generated accounts with `0.01` LIT and deposit `0.01` LIT into the Lit Ledger so we don't strand real mainnet balance.