Chore: Add forkdiff gh-page (#14)

### Description
we need a static webpage to show changes made to astria-geth fork, this
should be used both internally and externally.
using a [forkdiff](https://github.com/protolambda/forkdiff) tool to
create a static webpage.

### Changes
add a fork.yaml file structs the changes view and define the commits to
compare with
pages.yaml workflow deploys to gh-pages

Currently deploying on PR for testing.

.github/workflows/pages.yaml

@@ -0,0 +1,41 @@
+name: Build and publish forkdiff github-pages
+permissions:
+  contents: write
+on:
+  push:
+    branches:
+      - main
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 1000  # make sure to fetch the old commit we diff against
+
+      - name: Build forkdiff
+        uses: "docker://protolambda/forkdiff:latest"
+        with:
+          args: -repo=./ -fork=./fork.yaml -out=./index.html
+
+      - name: Build pages
+        run: |
+          mkdir -p ./tmp/pages
+          mv ./index.html ./tmp/pages/index.html
+          touch ./tmp/pages/.nojekyll
+
+      - name: Deploy
+        uses: peaceiris/actions-gh-pages@v3
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          # Build output to publish to the `gh-pages` branch:
+          publish_dir: ./tmp/pages
+          # The following lines assign commit authorship to the official
+          # GH-Actions bot for deploys to `gh-pages` branch:
+          # https://github.com/actions/checkout/issues/13#issuecomment-724415212
+          # The GH actions bot is used by default if you didn't specify the two fields.
+          # You can swap them out with your own user credentials.
+          user_name: github-actions[bot]
+          user_email: 41898282+github-actions[bot]@users.noreply.github.com
+

fork.yaml

@@ -0,0 +1,96 @@
+title: "astria-geth - go-ethereum fork diff overview"
+footer: |
+  Fork-diff overview of [`astria-geth`](https://github.com/astriaorg/astria-geth), a fork of [`go-ethereum`](https://github.com/ethereum/go-ethereum).
+base:
+  name: go-ethereum
+  url: https://github.com/ethereum/go-ethereum
+  hash: 916d6a441a866cb618ae826c220866de118899f7
+fork:
+  name: astria-geth
+  url: https://github.com/astriaorg/astria-geth
+  ref: refs/heads/main
+def:
+  title: "astria-geth"
+  description: |
+    This is an overview of the changes in [`astria-geth`](https://github.com/astriaorg/astria-geth),
+    a fork of [`go-ethereum`](https://github.com/ethereum/go-ethereum), part of the Astria-stack.
+
+    The Astria-stack architecture is modular, following the Consensus/Execution split of post-Merge Ethereum L1:
+      - [`astria-geth`](https://github.com/astriaorg/astria-geth) implements the Execution-Layer, with **minimal changes** for a secure Ethereum-equivalent application environment.
+
+    Related [astria-stack specifications](https://github.com/astriaorg/astria/tree/main/specs):
+  sub:
+    - title: "Core modifications"
+      sub:
+        - title: "Execution API"
+          description: |
+            The execution implements the [execution apiֿ](https://github.com/astriaorg/astria/blob/main/specs/execution-api.md) of the shared sequencer.
+            Its procedures will be called from the [conductor](https://github.com/astriaorg/astria/blob/main/specs/conductor.md). It is responsible
+            for immediately executing lists of ordered transactions that come from the shared sequencer.
+          globs:
+            - "grpc/execution/*"
+            - "grpc/*"
+        - title: "Tx-pool"
+          description: |
+            Transactions ordering as set by the shared sequencer
+          globs:
+            - "core/txpool/blobpool/*"
+            - "core/txpool/*"
+            - "core/txpool/legacypool/*"
+        - title: "State-transition modifications"
+          description: ""
+          sub:
+            - title: "Deposit Transaction type"
+              description: |
+                `Deposit` transaction type enable changes to the rollup based on sequencer layer events
+              globs:
+                - "core/types/deposit_tx.go"
+                - "core/types/transaction.go"
+                - "core/state_transition.go"
+                - "core/types/receipt.go"
+
+        - title: "Block-building modifications"
+          description: |
+            The block-building code implements changes to support shared sequencer transactions ordering.
+            Transactions are now being fethced from the `TxPool` based on the shared sequencer.
+          globs:
+            - "miner/*"
+    - title: "Node modifications"
+      description: Changes to the node configuration and services.
+      sub:
+        - title: Node config
+          globs:
+            - "node/config.go"
+            - "node/defaults.go"
+            - "node/grpcstack.go"
+            - "node/node.go"
+        - title: "CLI"
+          description: |
+            CLI changes to support grpc server.
+          globs:
+            - "cmd/utils/flags.go"
+            - "cmd/geth/main.go"
+            - "internal/flags/categories.go"
+            - "cmd/geth/config.go"
+    - title: "Chain Configuration"
+      sub:
+        - title: "Chain config"
+          description: |
+            Configuration changes for integrating the shared seuqnecer
+          globs:
+            - "params/config.go"
+            - "params/protocol_params.go"
+            - "core/genesis.go"
+            - "genesis.json"
+            - "core/blockchain.go"
+            - "eth/backend.go"
+
+# ignored globally, does not count towards line count
+ignore:
+  - ".circleci/*"
+  - "*.sum"
+  - "go.mod"
+  - "fork.yaml"
+  - ".github/*"
+  - ".github/workflows/*"
+