[#232] Use contract to get container info

Signed-off-by: Nikita Zinkevich <n.zinkevich@yadro.com>

docs/gate-configuration.md

@@ -60,6 +60,7 @@ $ cat http.log
 | `multinet`       | [Multinet configuration](#multinet-section)                    |
 | `features`       | [Features configuration](#features-section)                    |
 | `containers`     | [Containers configuration](#containers-section)                |
+| `contracts`      | [Contracts configuration](#contracts-section)                  |
 
 # General section
 
@@ -527,3 +528,15 @@ containers:
 | Parameter | Type     | SIGHUP reload | Default value | Description                             |
 |-----------|----------|---------------|---------------|-----------------------------------------|
 | `cors`    | `string` | no            |               | Container name for CORS configurations. |
+
+# `contracts` section
+
+```yaml
+contracts:
+  container:
+    name: container.frostfs
+```
+
+| Parameter        | Type     | SIGHUP reload | Default value       | Description                                  |
+|------------------|----------|---------------|---------------------|----------------------------------------------|
+| `container.name` | `string` | no            | `container.frostfs` | Container contract hash (LE) or name in NNS. |