auto-remove old thumbnails

Makefile

@@ -11,6 +11,7 @@ all:
 install: 
 	ln -sf "$(shell pwd)/3mfthumb" ~/.local/bin/
 	cp -lf 3mf.thumbnailer /home/k/.local/share/thumbnailers/
+    rm -rf ~/.cache/thumbnails
 
 clean:
 	rm -f *.o ${NAME}

README.md

@@ -24,14 +24,11 @@ We will assume you have a build environment such as `gcc-c++` and `make`.
 
 ## Build
 
-```make
+```
+make
 make install
 ```
 
-Remove generic thumbnails.
-
-`rm -rf ~/.cache/thumbnails`
-
 ## Developer logic
 
 The current version of the Lib3MF API uses the lib3mf_implicit.hpp header file instead of Lib3MF_Resources.hpp. This newer API provides a more simplified interface for working with the Lib3MF library.
@@ -43,6 +40,7 @@ The `Makefile` uses `pkg-config --cflags --libs lib3mf` to obtain the compiler f
 
 ## Issues
 
-We are new to C++ development, so there are bound to be some problems. Discuss issues on the [GitHub issue tracker](https://github.com/themanyone/3mfthumb/issues).
+We are new to C++ development, so there are bound to be some problems. 
+Discuss issues on the [GitHub issue tracker](https://github.com/themanyone/3mfthumb/issues).
 
-Copyright (C) 2023 Henry Kroll III, www.thenerdshow.com. See LICENSE for details.
+Copyright (C) 2023 Henry Kroll III, www.thenerdshow.com. See [LICENSE](LICENSE) for details.