feat: math chapter done + editorconfig + remove pycache

.editorconfig

@@ -0,0 +1,16 @@
+root = true
+
+# Unix-style newlines with a newline ending every file
+[*]
+end_of_line = lf
+insert_final_newline = true
+
+[*.{md,py}]
+charset = utf-8
+
+[*.py]
+indent_style = tab
+indent_size = 4
+
+[Makefile]
+indent_style = tab