Add nightly build badges for each branch (#351)

Author: Narukara

.github/workflows/nightly-humble.yml

@@ -0,0 +1,12 @@
+name: Nightly (humble)
+
+on:
+  schedule:
+    - cron: '0 4 * * *'
+  workflow_dispatch:
+
+jobs:
+  micro_ros_idf:
+    uses: ./.github/workflows/ci.yml
+    with:
+      branch: humble

.github/workflows/nightly-jazzy.yml

@@ -0,0 +1,12 @@
+name: Nightly (jazzy)
+
+on:
+  schedule:
+    - cron: '0 4 * * *'
+  workflow_dispatch:
+
+jobs:
+  micro_ros_idf:
+    uses: ./.github/workflows/ci.yml
+    with:
+      branch: jazzy

.github/workflows/nightly-kilted.yml

@@ -0,0 +1,12 @@
+name: Nightly (kilted)
+
+on:
+  schedule:
+    - cron: '0 4 * * *'
+  workflow_dispatch:
+
+jobs:
+  micro_ros_idf:
+    uses: ./.github/workflows/ci.yml
+    with:
+      branch: kilted

.github/workflows/nightly-rolling.yml

@@ -0,0 +1,12 @@
+name: Nightly (rolling)
+
+on:
+  schedule:
+    - cron: '0 4 * * *'
+  workflow_dispatch:
+
+jobs:
+  micro_ros_idf:
+    uses: ./.github/workflows/ci.yml
+    with:
+      branch: rolling

.github/workflows/nightly.yml

@@ -1,6 +1,10 @@
 ![banner](.images/banner-dark-theme.png#gh-dark-mode-only)
 ![banner](.images/banner-light-theme.png#gh-light-mode-only)
 
+| humble | jazzy | kilted | rolling |
+|:------:|:-----:|:------:|:-------:|
+| [![Nightly (humble)](https://github.com/micro-ROS/micro_ros_espidf_component/actions/workflows/nightly-humble.yml/badge.svg)](https://github.com/micro-ROS/micro_ros_espidf_component/actions/workflows/nightly-humble.yml) | [![Nightly (jazzy)](https://github.com/micro-ROS/micro_ros_espidf_component/actions/workflows/nightly-jazzy.yml/badge.svg)](https://github.com/micro-ROS/micro_ros_espidf_component/actions/workflows/nightly-jazzy.yml) | [![Nightly (kilted)](https://github.com/micro-ROS/micro_ros_espidf_component/actions/workflows/nightly-kilted.yml/badge.svg)](https://github.com/micro-ROS/micro_ros_espidf_component/actions/workflows/nightly-kilted.yml) | [![Nightly (rolling)](https://github.com/micro-ROS/micro_ros_espidf_component/actions/workflows/nightly-rolling.yml/badge.svg)](https://github.com/micro-ROS/micro_ros_espidf_component/actions/workflows/nightly-rolling.yml) |
+
 # micro-ROS component for ESP-IDF
 
 This component has been tested in ESP-IDF v5.2, v5.3, v5.4, and v5.5 with ESP32, ESP32-S2, ESP32-S3, ESP32-C3 and ESP32-C6.