hcwocl: add `README`, `Makefile`

hcwocl/Makefile

+CPPFLAGS = -I . -I TestBed/ -DCOMPUTE_DEVICE_CL -DCL_TARGET_OPENCL_VERSION=200
+CXXFLAGS = -std=c++20 -O2
+LDLIBS = -lglut -lGLU -lGL -lOpenCL -lpthread -lm
+
+OBJECTS = \
+	TestBed/main.o \
+	TestBed/Demos/Dem2Demo.o \
+	Common/Base/ThreadPool.o \
+	Common/Math/RadixSortHost.o
+
+.PHONY: all clean
+all: TestBed/TestBed
+
+clean:
+	rm -f $(OBJECTS)
+
+TestBed/TestBed: $(OBJECTS)
+	$(CXX) -o $@ $^ $(LDLIBS)

hcwocl/README.md

+Heterogeneous Computing with OpenCL
+===================================
+
+Particle simulation from chapter 10, modified to use portable code instead of
+Windows-only APIs.
+
+Based on the source code available in the website:
+
+http://www.heterogeneouscompute.org/?page_id=7
+
+See the website for copyright/license.
+
+building
+--------
+
+```
+$ make
+```
+
+demos
+-----
+
+![demo image](https://bbguimaraes.com/files/books/hcwocl.png)
+
+![demo video](https://bbguimaraes.com/files/books/hcwocl.webm)