update single include

Author: jbohanon

single_include/inja/inja.hpp

@@ -2127,7 +2127,11 @@ class Renderer : public NodeVisitor {
     if (value->is_string()) {
       std::string val;
       if (config.escape_strings) {
+        // get the value as a dump() to properly escape values
         val = value->dump();
+
+        // strip the leading and trailing " characters that are added by dump()
+        // if C++20 is adopted, val.starts_with and val.ends_with would clean this up a bit
         val = val.substr(0,1) == "\"" && val.substr(val.length()-1,1) == "\""
             ? val.substr(1, val.length()-2)
             : val;