Add doc for Git pre-push hook to block accidental pushes to main/master (#1012)

* Adding a doc on how to setup pre-push hook to forbid pushing to main/master

Author: rparolin

docs/pre-push-branch-check.md

@@ -0,0 +1,99 @@
+# 🔒 Prevent Accidental Pushes to `main`/`master` — With Emergency Override
+
+This guide shows you how to install a **Git pre‑push hook** that blocks pushes to branches (`main` or `master`) unless you explicitly set a noisy environment variable:
+
+```
+BREAK_GLASS_MAIN_PUSH=1
+```
+
+You can install this hook **globally** (affecting all your repos) or **per repo** (only in the specific repo you choose).
+Pick the option that best fits your workflow.
+
+---
+
+## 🛠 The Hook Script
+
+Both installation methods use the same script:
+
+```bash
+#!/bin/sh
+branch="$(git symbolic-ref --short HEAD)"
+
+if [ "$branch" = "main" ] || [ "$branch" = "master" ]; then
+    if [ "$BREAK_GLASS_MAIN_PUSH" = "1" ]; then
+        echo "⚠️ Override used: pushing to '$branch'..."
+    else
+        echo "❌ Push to '$branch' is disabled locally."
+        echo "   If you REALLY need to, run:"
+        echo "      BREAK_GLASS_MAIN_PUSH=1 git push origin $branch"
+        exit 1
+    fi
+fi
+```
+
+---
+
+## Option 1 — Install Globally (All Repos)
+
+This will protect every repo on your machine by default.
+
+1. Create a global hooks directory:
+    ```bash
+    mkdir -p ~/.git-hooks
+    ```
+
+2. Create the pre‑push hook:
+    ```bash
+    vim ~/.git-hooks/pre-push
+    ```
+    Paste the script above.
+
+3. Make it executable:
+    ```bash
+    chmod +x ~/.git-hooks/pre-push
+    ```
+
+4. Tell Git to use it globally:
+    ```bash
+    git config --global core.hooksPath ~/.git-hooks
+    ```
+
+---
+
+## Option 2 — Install Per Repo (Only One Project)
+
+This will protect only the repo you set it up in.
+
+1. Go to your repo:
+    ```bash
+    cd /path/to/your-repo
+    ```
+
+2. Create the pre‑push hook:
+    ```bash
+    vim .git/hooks/pre-push
+    ```
+    Paste the script above.
+
+3. Make it executable:
+    ```bash
+    chmod +x .git/hooks/pre-push
+    ```
+
+---
+
+## ✅ Testing
+
+1. Try pushing to `main` without override:
+    ```bash
+    git push origin main
+    ```
+    ➡ Should be **blocked**.
+
+2. Try with override:
+    ```bash
+    BREAK_GLASS_MAIN_PUSH=1 git push origin main
+    ```
+    ➡ Allowed with warning.
+
+---