Standardise code directory names (#920)

* Rename c++ directories to cpp

* Rename golang folders to go

* Change paths to code in chapter files

Co-authored-by: James Schloss <[email protected]>

Author: ShadowMitia

contents/IFS/IFS.md

@@ -135,7 +135,7 @@ Here, instead of tracking children of children, we track a single individual tha
 {% sample lang="hs" %}
 [import:7-13, lang:"haskell"](code/haskell/IFS.hs)
 {% sample lang="cpp" %}
-[import:39-52, lang:"cpp"](code/c++/IFS.cpp)
+[import:39-52, lang:"cpp"](code/cpp/IFS.cpp)
 {% sample lang="py" %}
 [import:5-12, lang:"python"](code/python/IFS.py)
 {% sample lang="c" %}
@@ -221,7 +221,7 @@ In addition, we have written the chaos game code to take in a set of points so t
 {% sample lang="hs" %}
 [import, lang:"haskell"](code/haskell/IFS.hs)
 {% sample lang="cpp" %}
-[import, lang:"cpp"](code/c++/IFS.cpp)
+[import, lang:"cpp"](code/cpp/IFS.cpp)
 {% sample lang="py" %}
 [import, lang:"python"](code/python/IFS.py)
 {% sample lang="c" %}