fix: use clang instead of gcc on BSD

GNUmakefile

@@ -86,6 +86,10 @@ ifeq ($(shell uname), Darwin)
   CC = clang
   MACOS_SPECIFIC_CFLAGS_OPTS  = -x objective-c
   MACOS_SPECIFIC_LDFLAGS_OPTS = -framework Cocoa -framework Carbon -framework CoreVideo -framework OpenGL -framework IOKit
+else ifeq ($(shell uname), FreeBSD)
+  CC = clang
+else ifeq ($(shell uname), OpenBSD)
+  CC = clang
 endif
 AR = ar -rc
 ifdef Q_RSC
@@ -117,6 +121,7 @@ endif
 define RAYLIB_CPPFLAGS
   $(DISABLE_ASSERTS_OPTS)        \
   -D PLATFORM_DESKTOP            \
+  -isystem /usr/local/$(HDR_DIR) \
   -isystem /usr/X11R6/$(HDR_DIR) \
   -isystem $(RAYLIB_SRC_DIR)     \
   -isystem $(RAYLIB_SRC_DIR)/external/glfw/$(HDR_DIR)

README.org

@@ -111,6 +111,7 @@ You should have received a copy of the GNU General Public License along with Spa
     - [[#freebsd][FreeBSD]]
     - [[#openbsd][OpenBSD]]
     - [[#macos][macOS]]
+  - [[#compilation--linkage][Compilation & Linkage]]
 
 * Project's Roadmap
 
@@ -156,7 +157,7 @@ git clone --recurse-submodules https://github.com/iWas-Coder/sparky
 These are the packages needed to be able to build /Sparky/ from source, they are divided by distribution/package manager. Also, a command for each one is added to make the installation of these development dependencies as easy and straightforward as possible.
 
 - ~make~
-- ~gcc~
+- ~gcc~ / ~clang~
 - ~rust~
 - ~jq~
 - ~libX11~
@@ -192,18 +193,21 @@ sudo emerge -va make gcc rust-bin jq libX11 libXcursor libXrandr libXinerama lib
 *** FreeBSD
 
 #+begin_src sh
-sudo pkg install gmake gcc rust jq libX11 libXcursor libXrandr libXinerama libXi
+sudo pkg install gmake rust jq libX11 libXcursor libXrandr libXinerama libXi
 #+end_src
 
 *** OpenBSD
 
 #+begin_src sh
-sudo pkg_add gmake gcc rust jq
-sudo ln -s /usr/local/bin/x86_64-unknown-openbsd*-gcc-* /usr/local/bin/gcc
+sudo pkg_add gmake rust jq
 #+end_src
 
 *** macOS
 
 #+begin_src sh
 brew install rust jq
 #+end_src
+
+** Compilation & Linkage
+
+(...)