Combine the error types.

src/parser/paragraph.rs

@@ -1,3 +1,6 @@
+use crate::error::CustomError;
+use crate::error::MyError;
+use crate::error::Res;
 use nom::branch::alt;
 use nom::combinator::eof;
 use nom::combinator::recognize;
@@ -16,7 +19,6 @@ use crate::parser::util::maybe_consume_trailing_whitespace_if_not_exiting;
 use crate::parser::util::start_of_line;
 
 use super::element_parser::non_paragraph_element;
-use super::error::Res;
 use super::lesser_element::Paragraph;
 use super::util::blank_line;
 use super::util::get_consumed;