Remove unnecessary resources, add bulma, and add AdvMakefile

bulma/node_modules/node-sass/src/libsass/docs/custom-functions-internal.md

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+# Developer Documentation
+
+Custom functions are internally represented by `struct Sass_C_Function_Descriptor`.
+
+## Sass_C_Function_Descriptor
+
+```C
+struct Sass_C_Function_Descriptor {
+  const char*      signature;
+  Sass_C_Function  function;
+  void*            cookie;
+};
+```
+
+- `signature`: The function declaration, like `foo($bar, $baz:1)`
+- `function`:  Reference to the C function callback
+- `cookie`:    any pointer you want to attach
+
+### signature
+
+The signature defines how the function can be invoked. It also declares which arguments are required and which are optional.  Required arguments will be enforced by LibSass and a Sass error is thrown in the event a call as missing an argument. Optional arguments only need to be present when you want to overwrite the default value.
+
+    foo($bar, $baz: 2)
+
+In this example, `$bar` is required and will error if not passed. `$baz` is optional and the default value of it is 2. A call like `foo(10)` is therefore equal to `foo(10, 2)`, while `foo()` will produce an error.
+
+### function
+
+The callback function needs to be of the following form:
+
+```C
+union Sass_Value* call_sass_function(
+    const union Sass_Value* s_args,
+    void*                   cookie
+) {
+  return sass_clone_value(s_args);
+}
+```
+
+### cookie
+
+The cookie can hold any pointer you want. In the `perl-libsass` implementation it holds the structure with the reference of the actual registered callback into the perl interpreter. Before that call `perl-libsass` will convert all `Sass_Values` to corresponding perl data types (so they can be used natively inside the perl interpretor). The callback can also return a `Sass_Value`. In `perl-libsass` the actual function returns a perl value, which has to be converted before `libsass` can work with it again!
+
+## Sass_Values
+
+```C
+// allocate memory (copies passed strings)
+union Sass_Value* sass_make_null    (void);
+union Sass_Value* sass_make_boolean (bool val);
+union Sass_Value* sass_make_string  (const char* val);
+union Sass_Value* sass_make_qstring (const char* val);
+union Sass_Value* sass_make_number  (double val, const char* unit);
+union Sass_Value* sass_make_color   (double r, double g, double b, double a);
+union Sass_Value* sass_make_list    (size_t len, enum Sass_Separator sep, bool is_bracketed);
+union Sass_Value* sass_make_map     (size_t len);
+union Sass_Value* sass_make_error   (const char* msg);
+union Sass_Value* sass_make_warning (const char* msg);
+
+// Make a deep cloned copy of the given sass value
+union Sass_Value* sass_clone_value (const union Sass_Value* val);
+
+// deallocate memory (incl. all copied memory)
+void sass_delete_value (const union Sass_Value* val);
+```
+
+## Example main.c
+
+```C
+#include <stdio.h>
+#include <stdint.h>
+#include "sass/context.h"
+
+union Sass_Value* call_fn_foo(const union Sass_Value* s_args, void* cookie)
+{
+  // we actually abuse the void* to store an "int"
+  return sass_make_number((size_t)cookie, "px");
+}
+
+int main( int argc, const char* argv[] )
+{
+
+  // get the input file from first argument or use default
+  const char* input = argc > 1 ? argv[1] : "styles.scss";
+
+  // create the file context and get all related structs
+  struct Sass_File_Context* file_ctx = sass_make_file_context(input);
+  struct Sass_Context* ctx = sass_file_context_get_context(file_ctx);
+  struct Sass_Options* ctx_opt = sass_context_get_options(ctx);
+
+  // allocate a custom function caller
+  Sass_C_Function_Callback fn_foo =
+    sass_make_function("foo()", call_fn_foo, (void*)42);
+
+  // create list of all custom functions
+  Sass_C_Function_List fn_list = sass_make_function_list(1);
+  sass_function_set_list_entry(fn_list, 0, fn_foo);
+  sass_option_set_c_functions(ctx_opt, fn_list);
+
+  // context is set up, call the compile step now
+  int status = sass_compile_file_context(file_ctx);
+
+  // print the result or the error to the stdout
+  if (status == 0) puts(sass_context_get_output_string(ctx));
+  else puts(sass_context_get_error_message(ctx));
+
+  // release allocated memory
+  sass_delete_file_context(file_ctx);
+
+  // exit status
+  return status;
+
+}
+```
+
+## Compile main.c
+
+```bash
+gcc -c main.c -o main.o
+gcc -o sample main.o -lsass
+echo "foo { margin: foo(); }" > foo.scss
+./sample foo.scss => "foo { margin: 42px }"
+```