Fix typo in AccelerometerSensor documentation

Change-Id: I755616e4c18d77011baaa96dbe852939ee643681

appinventor/appengine/src/com/google/appinventor/client/OdeMessages.java

@@ -5577,7 +5577,7 @@ public interface OdeMessages extends Messages {
   String MockSpinnerAddItems();
 
   //help strings
-  @DefaultMessage("Non-visible component that can detect shaking and measure acceleration approximately in three dimensions using SI units (m/s<sup>2</sup>).  The components are: <ul>\n<li> <strong>xAccel</strong>: 0 when the phone is at rest on a flat      surface, positive when the phone is tilted to the right (i.e.,      its left side is raised), and negative when the phone is tilted      to the left (i.e., its right size is raised).</li>\n <li> <strong>yAccel</strong>: 0 when the phone is at rest on a flat      surface, positive when its bottom is raised, and negative when      its top is raised. </li>\n <li> <strong>zAccel</strong>: Equal to -9.8 (earth\"s gravity in meters per      second per second when the device is at rest parallel to the ground      with the display facing up,      0 when perpindicular to the ground, and +9.8 when facing down.       The value can also be affected by accelerating it with or against      gravity. </li></ul>")
+  @DefaultMessage("Non-visible component that can detect shaking and measure acceleration approximately in three dimensions using SI units (m/s<sup>2</sup>).  The components are: <ul>\n<li> <strong>xAccel</strong>: 0 when the phone is at rest on a flat      surface, positive when the phone is tilted to the right (i.e.,      its left side is raised), and negative when the phone is tilted      to the left (i.e., its right size is raised).</li>\n <li> <strong>yAccel</strong>: 0 when the phone is at rest on a flat      surface, positive when its bottom is raised, and negative when      its top is raised. </li>\n <li> <strong>zAccel</strong>: Equal to -9.8 (earth\"s gravity in meters per      second per second when the device is at rest parallel to the ground      with the display facing up,      0 when perpendicular to the ground, and +9.8 when facing down.       The value can also be affected by accelerating it with or against      gravity. </li></ul>")
   @Description("")
   String AccelerometerSensorHelpStringComponentPallette();
 

appinventor/components/src/com/google/appinventor/components/runtime/AccelerometerSensor.java

@@ -60,7 +60,7 @@ import java.util.Queue;
     "<li> <strong>zAccel</strong>: Equal to -9.8 (earth's gravity in meters per " +
     "     second per second when the device is at rest parallel to the ground " +
     "     with the display facing up, " +
-    "     0 when perpindicular to the ground, and +9.8 when facing down.  " +
+    "     0 when perpendicular to the ground, and +9.8 when facing down.  " +
     "     The value can also be affected by accelerating it with or against " +
     "     gravity. </li></ul>",
     category = ComponentCategory.SENSORS,

appinventor/docs/reference/components/sensors.html

@@ -467,7 +467,7 @@
 <p>Non-visible component that can detect shaking and measure acceleration approximately in three dimensions using SI units (m/s<sup>2</sup>).  The components are: <ul>
 <li> <strong>xAccel</strong>: 0 when the phone is at rest on a flat      surface, positive when the phone is tilted to the right (i.e.,      its left side is raised), and negative when the phone is tilted      to the left (i.e., its right size is raised).</li>
  <li> <strong>yAccel</strong>: 0 when the phone is at rest on a flat      surface, positive when its bottom is raised, and negative when      its top is raised. </li>
- <li> <strong>zAccel</strong>: Equal to -9.8 (earth's gravity in meters per      second per second when the device is at rest parallel to the ground      with the display facing up,      0 when perpindicular to the ground, and +9.8 when facing down.       The value can also be affected by accelerating it with or against      gravity. </li></ul></p>
+ <li> <strong>zAccel</strong>: Equal to -9.8 (earth's gravity in meters per      second per second when the device is at rest parallel to the ground      with the display facing up,      0 when perpendicular to the ground, and +9.8 when facing down.       The value can also be affected by accelerating it with or against      gravity. </li></ul></p>
 
 <h3>Properties</h3>
 <dl>