Reflow all the language stack README-content.md files to 80 columns and incorporate Fred's changes

This also includes Fred's updates to the `README-short.txt` files, and a bunch of very minor changes for consistency (using "PHP" instead of "php", ending sentences that describe and lead into a code block with a ":", using "Go" instead of "Golang" and "Hy" instead of "Hylang" within prose, not using periods at the end of headlines, etc).

A really fun one included here is that Java mentioned both using GNU Make inside the container (and `java` doesn't include `make` presently), and some of the prose mentioned `go build` after we ran `javac`, which was extra neat.

python/README-content.md

@@ -1,12 +1,19 @@
 # What is Python?
 
-Python is a widely used general-purpose, high-level programming language. Its design philosophy emphasizes code readability, and its syntax allows programmers to express concepts in fewer lines of code than would be possible in languages such as C. The language provides constructs intended to enable clear programs on both a small and large scale.
+Python is an interpreted, interactive, object-oriented, open-source programming
+language. It incorporates modules, exceptions, dynamic typing, very high level
+dynamic data types, and classes. Python combines remarkable power with very
+clear syntax. It has interfaces to many system calls and libraries, as well as
+to various window systems, and is extensible in C or C++. It is also usable as
+an extension language for applications that need a programmable interface.
+Finally, Python is portable: it runs on many Unix variants, on the Mac, and on
+Windows 2000 and later.
 
 > [wikipedia.org/wiki/Python_(programming_language)](https://en.wikipedia.org/wiki/Python_(programming_language))
 
 # How to use this image
 
-## Create a `Dockerfile` in your python app project.
+## Create a `Dockerfile` in your Python app project
 
     FROM python:3
     COPY . /usr/src/myapp
@@ -20,14 +27,16 @@ or (if you need to use Python 2):
     WORKDIR /usr/src/myapp
     CMD [ "python", "./your-daemon-or-script.py" ]
 
-Then build and run the docker image.
+You can then build and run the Docker image:
 
     docker build -t my-python-app
     docker run -it --rm --name my-running-app my-python-app
 
-## Run a single python script.
+## Run a single Python script
 
-For many single file projects, it may not be convenient to write a `Dockerfile` for your project. In such cases, you can run a python script by using the python docker image directly.
+For many simple, single file projects, you may find it inconvenient to write a
+complete `Dockerfile`. In such cases, you can run a Python script by using the
+Python Docker image directly:
 
     docker run -it --rm --name my-running-script -v "$(pwd)":/usr/src/myapp -w /usr/src/myapp python:3 python your-daemon-or-script.py
 

python/README-short.txt

@@ -1 +1 @@
-Python is a widely used general-purpose, high-level programming language.
+Python is an interpreted, interactive, object-oriented, open-source programming language. It incorporates modules, exceptions, dynamic typing, very high level dynamic data types, and classes.