ci: support releasing proto definitions to BSR (#274)

Adds support for pushing the proto definitions to BSR

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- **New Features**
- Introduced a continuous integration (CI) workflow for automated checks
on Protocol Buffers.
	- Added a new module configuration for managing protocol buffers.

- **Documentation**
	- New workflow file created to outline CI processes.
	- Configuration file established for module versioning and structure.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: Rootul P <[email protected]>

.github/workflows/buf-ci.yaml

@@ -0,0 +1,29 @@
+name: buf-ci
+on:
+  push:
+    branches:
+      - main
+    tags:
+      - "v[0-9]+.[0-9]+.[0-9]+"
+      - "v[0-9]+.[0-9]+.[0-9]+-alpha.[0-9]+"
+      - "v[0-9]+.[0-9]+.[0-9]+-beta.[0-9]+"
+      - "v[0-9]+.[0-9]+.[0-9]+-rc[0-9]+"
+  pull_request:
+permissions:
+  contents: read
+  pull-requests: write
+jobs:
+  buf:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: bufbuild/buf-action@v1
+        with:
+          token: ${{ secrets.BUF_TOKEN }}
+          input: "pb"
+          breaking-against: 'https://github.com/celestiaorg/nmt.git#branch=main,ref=HEAD~1,subdir=pb'
+          # Run breaking change, lint, and format checks for Protobuf sources against all branches,
+          # 'pb' subdirectory, then push to the Buf Schema Registry once validated
+          lint: true
+          format: true
+          breaking: true

buf.yaml

@@ -0,0 +1,12 @@
+version: v2
+modules:
+  - path: pb
+    name: buf.build/celestia/nmt
+lint:
+  ignore_only:
+    PACKAGE_DIRECTORY_MATCH:
+      # ignoring because fixing means we will do a breaking change
+      - pb/proof.proto
+    PACKAGE_VERSION_SUFFIX:
+      # ignoring because fixing means we will do a breaking change
+      - pb/proof.proto

pb/proof.proto

@@ -1,15 +1,15 @@
-syntax="proto3";
+syntax = "proto3";
 
 package proof.pb;
 
 option go_package = "github.com/celestiaorg/nmt/pb";
 
 message Proof {
   // Start index of the leaves that match the queried namespace.ID.
-  int64 start     = 1;
+  int64 start = 1;
   // End index (non-inclusive) of the leaves that match the queried
   // namespace.ID.
-  int64 end       = 2;
+  int64 end = 2;
   // Nodes hold the tree nodes necessary for the Merkle range proof.
   repeated bytes nodes = 3;
   // leaf_hash contains the namespace.ID if NMT does not have it and
@@ -18,5 +18,5 @@ message Proof {
   bytes leaf_hash = 4;
   // The is_max_namespace_ignored flag influences the calculation of the
   // namespace ID range for intermediate nodes in the tree.
-  bool is_max_namespace_ignored=5;
-}
+  bool is_max_namespace_ignored = 5;
+}