Updated readme for release 3.1.0.

This adds a section about the new commands, updates out-of-date
references, and highlights the translator as the currently most
interesting component.

doc/building.md

@@ -2,42 +2,45 @@
 
 `plasp` requires a C++17 compiler (preferably GCC ≥ 6.1 or clang ≥ 3.8) and CMake for building.
 
-```bash
-$ git clone https://github.com/potassco/plasp.git
-$ cd plasp
-$ mkdir -p build/release
-$ cd build/release
-$ cmake ../.. -DCMAKE_BUILD_TYPE=Release
-$ make
+```sh
+git clone https://github.com/potassco/plasp.git
+cd plasp
+mkdir -p build/release
+cd build/release
+cmake ../.. -DCMAKE_BUILD_TYPE=Release
+make
 ```
 
 The built `plasp` binary is then located at `plasp/build/release/bin/plasp`.
 
 To update `plasp` to the most recent version, perform the following steps:
 
-```bash
-$ cd plasp
-$ git pull
-$ cd build/release
-$ cmake .
-$ make
+```sh
+cd plasp
+git checkout master
+git pull
+cd build/release
+cmake .
+make
 ```
 
 ## Running the Tests
 
-`plasp` provides unit tests written using the [Catch](https://github.com/philsquared/Catch) framework.
-Before building and running the tests, make sure you have fetched the Catch git submodule:
+`plasp` provides unit tests written with [Catch2](https://github.com/catchorg/Catch2).
+Before building and running the tests, make sure you have fetched the Catch submodule:
 
-```bash
-$ git submodule init
-$ git submodule update
+```sh
+git submodule init
+git submodule update
 ```
 
 Afterward, enable the flag `BUILD_TESTS` in your CMake configuration.
 Finally, build and run the tests as follows:
 
-```bash
-$ make run-tests
+```sh
+make run-tokenize-tests
+make run-pddl-tests
+make run-tests
 ```
 
 After updating `plasp`, make sure to execute CMake again in order for the tests to run correctly.