chore: add spec files, tx short description

.github/README.md

@@ -3,3 +3,5 @@
 [![codecov](https://img.shields.io/codecov/c/gh/noble-assets/authority?token=QNKNK03VIR&labelColor=black)](https://codecov.io/gh/noble-assets/authority)
 
 This repository includes the `x/authority` Cosmos SDK module implementation.
+
+For more information, refer to the modules [spec](../x/authority/spec) files.

x/authority/client/cli/tx.go

@@ -25,7 +25,7 @@ func GetTxCmd() *cobra.Command {
 func NewCmdExecute() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "execute [path to underlying tx file]",
-		Short: "",
+		Short: "Execute arbitrary messages as authority module",
 		Args:  cobra.ExactArgs(1),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			clientCtx, err := client.GetClientTxContext(cmd)

x/authority/spec/01_state.md

@@ -0,0 +1,16 @@
+# State
+
+## Authority
+
+The authority field is of type bytes, specifically a Noble address, stored via an [`collections.Item`][item].
+It is used to store the current underlying authority address of this module.
+
+```go
+var AuthorityKey = []byte("authority")
+```
+
+It is updated by the following messages:
+
+- [`noble.authority.v1.UpdateAuthority`](./02_messages.md#update-authority)
+
+[item]: https://docs.cosmos.network/main/build/packages/collections#item

x/authority/spec/02_messages.md

@@ -0,0 +1,91 @@
+# Messages
+
+## Execute
+
+`noble.authority.v1.MsgExecute`
+
+A message to execute arbitrary messages on behalf of the `x/authority` module.
+If other module authorities are configured to this module, this can be used to
+execute admin messages such as updating params, software ugprades, etc.
+
+```shell
+auth_info:
+  fee:
+    amount: []
+    gas_limit: "200000"
+    granter: ""
+    payer: ""
+  signer_infos: []
+  tip: null
+body:
+  extension_options: []
+  memo: ""
+  messages:
+  - '@type': /noble.authority.v1.MsgExecute
+    messages: [...]
+    signer: noble1authority
+  non_critical_extension_options: []
+  timeout_height: "0"
+signatures: []
+```
+
+### Arguments
+
+- `messages` — An array of encoded messages to execute.
+
+### Requirements
+
+- Signer must be the current underlying [`authority`](./01_state.md#authority).
+
+### State Changes
+
+This message doesn't affect any `x/authority` state.
+
+However, the executed messages may contain state changes.
+
+### Events Emitted
+
+This message emits no events.
+
+## Update Authority
+
+`noble.authority.v1.MsgUpdateAuthority`
+
+A message that updates the underlying authority of this module.
+
+```shell
+auth_info:
+  fee:
+    amount: []
+    gas_limit: "200000"
+    granter: ""
+    payer: ""
+  signer_infos: []
+  tip: null
+body:
+  extension_options: []
+  memo: ""
+  messages:
+  - '@type': /noble.authority.v1.MsgUpdateAuthority
+    new_authority: noble1demo
+    signer: noble1authority
+  non_critical_extension_options: []
+  timeout_height: "0"
+signatures: []
+```
+
+### Arguments
+
+- `new_authority` — The Noble address to transfer underlying authority to.
+
+### Requirements
+
+- Signer must be the current underlying [`authority`](./01_state.md#authority).
+
+### State Changes
+
+- [`authority`](./01_state.md#authority)
+
+### Events Emitted
+
+This message emits no events.