Fix section numbering in notebook 03.

Author: jeffcarlin

03_Image_Display_and_Manipulation.ipynb

@@ -130,7 +130,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### 1. Load the LSST Science Pipelines\n",
+    "### 2. Load the LSST Science Pipelines\n",
     "\n",
     "First, we load the `lsst.afw.display` library to gain access to the image visualization routines we'd like to use, and the `lsst.daf.butler` library, which is used to access data products."
    ]
@@ -151,7 +151,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### 2. Load the Data to Visualize\n",
+    "### 3. Load the Data to Visualize\n",
     "\n",
     "To display an image, we must first load some data. These data have been processed with the LSST Science Pipelines, and are organized in a structure that enables us to access them through the `Butler`. For more information on the `Butler`, see [lsst.daf.butler](https://pipelines.lsst.io/modules/lsst.daf.butler/index.html).\n",
     "\n",
@@ -188,7 +188,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### 3.1: Use AFWDisplay to Visualize the Image\n",
+    "### 4.1: Use AFWDisplay to Visualize the Image\n",
     "\n",
     "Now, with a `Butler` instance defined and a calibrated exposure retrieved, we can use [`lsst.afw.display`](https://github.com/lsst/afw/tree/master/python/lsst/afw/display) to visualize the data.  The next task is to let AFWDisplay know that we want it to use `matplotlib` as our default display backend. To do this, we use the `setDefaultBackend()` function. Remember that we made an alias to `lsst.afw.display` called `afwDisplay`, so we'll use that to call `setDefaultBackend()`."
    ]
@@ -322,7 +322,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### 3.2: Use AFWDisplay to Visualize the Image and Mask Plane\n",
+    "### 4.2: Use AFWDisplay to Visualize the Image and Mask Plane\n",
     "\n",
     "The `calexp` returned by the butler contains more than just the image pixel values (see the Stack Club [calexp tutorial](https://github.com/LSSTScienceCollaborations/StackClub/blob/master/Basics/Calexp_guided_tour.ipynb) for more details). One other component is the mask plane associated with the image. `afwDisplay` provides a nice pre-packaged interface for overplotting the mask associated with an image. A mask is composed of a set of \"mask planes,\" 2D binary bit maps corresponding to pixels that are masked for various reasons (see [here](https://pipelines.lsst.io/v/DM-11392/getting-started/display.html#interpreting-displayed-mask-colors) for more details)."
    ]
@@ -383,7 +383,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### 4. More Information about lsst.afw.display\n",
+    "### 5. More Information about lsst.afw.display\n",
     "\n",
     "To get some more information about `lsst.afw.display`, we can print the method list to see what's available. The next cell will print `lsst.afw.display` methods to the screen."
    ]
@@ -429,7 +429,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### 5. Extract a cutout image\n",
+    "### 6. Extract a cutout image\n",
     "\n",
     "Say we want to grab a cutout of the DP0.1 coadded images at a specific location. In order to do this, we need a few other packages from the LSST Science Pipelines. In particular, we'll need access to the geometry and coordinate packages."
    ]
@@ -617,7 +617,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### 6. Plot an RGB composite image\n",
+    "### 7. Plot an RGB composite image\n",
     "\n",
     "That's a pretty cluster, but what if we really want to know about the colors of the stars and galaxies in that image? To do that, we can extract images taken with three different filters, then assign those images to the RGB channels of a color image.\n",
     "\n",