add period to alt text per accessibility recommendation

docs/source/programming_resources/shared/choosing_program_lang/choosing-program-lang.rst

@@ -20,7 +20,7 @@ who prefer to design their op modes visually, using a drag-and-drop
 interface.
 
 .. image:: images/BlocksPicture1.jpg
-   :alt: Blocks Programming Tool showing a graphical Blocks program
+   :alt: Blocks Programming Tool showing a graphical Blocks program.
 
 The OnBot Java Programming Tool
 -------------------------------
@@ -31,7 +31,7 @@ have basic to advanced Java skills and who would like to write
 text-based op modes.
 
 .. image:: images/onBotJavaScreen.jpg
-   :alt: OnBot Java Programming Tool showing Java source code
+   :alt: OnBot Java Programming Tool showing Java source code.
 
 Android Studio
 --------------
@@ -42,7 +42,7 @@ recommended for advanced users who have extensive Java programming
 experience.
 
 .. image:: images/androidStudioScreen.jpg
-   :alt: Android Studio showing Java source code
+   :alt: Android Studio showing Java source code.
 
 Recommendations
 ---------------
@@ -58,7 +58,7 @@ Tool. However, OnBot Java is a text-based tool and it requires that the
 user have a sound understanding of the Java programming language.
 
 .. image:: images/ipadPhoneChromebook.jpg
-   :alt: A tablet, a phone, and a laptop each showing the programming tools in use
+   :alt: A tablet, a phone, and a laptop each showing the programming tools in use.
 
 It is important to note that with the Blocks Programming Tool and the
 OnBot Java Programming Tool, a user only needs a web browser to create,