[#906] neofs-adm: Add README file

Signed-off-by: Alex Vanin <alexey@nspcc.ru>

cmd/neofs-adm/README.md

@@ -0,0 +1,99 @@
+# NeoFS Admin Tool
+
+## Overview
+
+Admin tool provides an easier way to deploy and maintain private installation
+of NeoFS. Private installation contains a set of consensus N3 nodes, NeoFS 
+Alphabet, and Storage nodes. Admin tool generates consensus keys, initializes 
+side chain and provides functions to update the network and register new
+Storage nodes.
+
+## Build
+
+To build binary locally use `make bin/neofs-adm` command. 
+
+For clean build inside docker container use `make docker/bin/neofs-adm`. 
+
+Build docker image with `make image-adm`.
+
+At NeoFS private install deployment, neofs-adm requires compiled NeoFS 
+contracts. Find them in the latest release of 
+[neofs-contract repository](https://github.com/nspcc-dev/neofs-contract/releases).
+
+
+## Commands
+
+### Config
+
+Config section provides `init` command that creates configuration file for the
+private installation deployment and updates. Config file is optional, all
+parameters may be passed by arguments or read from standard input (wallet 
+passwords).
+
+Config example:
+```yaml
+rpc-endpoint: https://address:port # side chain RPC node endpoint
+alphabet-wallets: /path            # path to consensus node / alphabet wallets storage
+network:
+  max_object_size: 67108864 # max size of single NeoFS object, bytes
+  epoch_duration: 240       # duration of NeoFS epoch in blocks, consider block generation frequency in side chain
+  basic_income_rate: 0      # basic income rate, for private consider 0
+  fee:
+    audit: 0     # network audit fee, for private installation consider 0
+    candidate: 0 # inner ring candidate registration fee, for private installation consider 0
+    container: 0 # container creation fee, for private installation consider 0
+    withdraw: 0  # withdraw fee, for private installation consider 0
+credentials:     # passwords for consensus node / alphabet wallets
+  az: ...
+  buky: ...
+  vedi: ...
+  glagoli: ...
+  dobro: ...
+  yest: ...
+  zhivete: ...
+```
+
+### Morph
+
+#### Network deployment
+
+- Use `generate-alphabet` to generate set of wallets for consensus and 
+  Alphabet nodes. 
+
+- `init` will initialize side chain by deploying smart contracts and
+  setting provided NeoFS network configuration.
+
+- `generate-storage-wallet` generates wallet for the Storage node that 
+  is ready for deployment. It also transfers a bit of side chain GAS so this 
+  wallet can be used for NeoFS bootstrap.
+
+#### Network maintenance
+
+- `force-new-epoch` increments NeoFS epoch number and enforces new epoch
+  handlers in NeoFS nodes.
+
+- `refill-gas` transfers side chain GAS to specified wallet. 
+
+- `update-contracts` starts contract update routine.
+
+#### Container migration
+
+If network has to be redeployed, these commands will migrate all container meta
+info. These commands **do not migrate actual objects**.
+
+- `dump-containers` saves all containers and metadata registered in container
+  contract to a file.
+
+- `restore-containers` restores previously saved containers in container
+  contract.
+
+#### Network info
+
+- `dump-config` prints NeoFS network configuration.
+
+- `dump-hashes` prints NeoFS contract addresses stored in NNS.
+
+
+## Private network deployment
+
+Read step-by-step guide of private storage deployment [in docs](./docs/deploy.md).