Fix problems with missing newline at eof

Cargo.lock

@@ -1117,7 +1117,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "snekdown"
-version = "0.21.0"
+version = "0.21.1"
 dependencies = [
  "asciimath-rs 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "base64 0.12.3 (registry+https://github.com/rust-lang/crates.io-index)",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "snekdown"
-version = "0.21.0"
+version = "0.21.1"
 authors = ["trivernis <trivernis@protonmail.com>"]
 edition = "2018"
 license-file = "LICENSE"

src/parser/mod.rs

@@ -99,6 +99,9 @@ impl Parser {
         reader
             .read_to_string(&mut text)
             .expect("Failed to read file");
+        if text.chars().last() != Some('\n') {
+            text.push('\n');
+        }
 
         let document = Document::new(!is_child);
         Self {