added a basic readme.

added IDE files to gitignore.

.gitignore

@@ -1,3 +1,5 @@
 /target
 **/*.rs.bk
-sample/
+sample/
+nginx-log-parser.iml
+.idea/

README.md

@@ -0,0 +1,17 @@
+# nginx_log_parser
+
+A rust library to read nginx log files.
+
+Takes a nginx-like syntax for the format and generates a parser that reads log lines.
+```rust
+extern crate nginx_log_parser;
+use nginx_log_parser::Format;
+
+let format = Format::from_str("$remote_addr [$time_local] $request").unwrap();
+let entry = format.parse("1.2.3.4 [11/Sep/2018:08:44:17 +0000] GET / HTTP/1.1");
+assert_eq!(Some("GET / HTTP/1.1"), entry.unwrap().get("request"));
+```
+
+## To be done
+ - more tests
+ - make the parser fast (do not use a full-featured-regex engine)