add readme and example

README.md

@@ -1,3 +1,60 @@
 # wildcard
 
-A simple golang wildcard matcher. Golang has pretty well built regex functionalities, but it does not have wildcard matcher that works as nicely. Therefore this package serves the need to check whether a string matches a pattern in the rule of wildcard.
+A simple golang customizable [wildcard](https://en.wikipedia.org/wiki/Wildcard_character) matcher. Golang has pretty well built regex functionalities, but it does not have basic wildcard matcher that works as nicely. Therefore this package serves the need to check whether a string matches a pattern in the rule of wildcard.
+
+To keep simplicity, the matcher support only two rules:
+- `"?"` for a single char.
+- `"*"` for any number (including zero) of chars.
+
+Charset like `"[A-Za-z]"` or SQL style wild cards like `%` are not supported.
+
+## Usage
+
+To import the package, `go get` the module.
+
+```
+go get -u github.com/vodkaslime/wildcard@main
+```
+
+
+
+To match pattern, use a matcher.
+
+```
+package main
+
+import (
+	"github.com/vodkaslime/wildcard"
+)
+
+func main() {
+	matcher := wildcard.NewMatcher()
+	p := "a?c"
+	s := "abc"
+	m, _ := matcher.Match(p, s)
+	println(m)
+}
+
+```
+
+The default wildcard chars are `"?"` for single chars and `"*"` for multiple chars. To customize this rule, tune the `S` field or `M` field accordingly.
+
+For example to use `"."` as single char wildcard symbol:
+
+```
+package main
+
+import (
+	"github.com/vodkaslime/wildcard"
+)
+
+func main() {
+	matcher := wildcard.NewMatcher()
+	matcher.S = '.'
+	p := "a.c"
+	s := "abc"
+	m, _ := matcher.Match(p, s)
+	println(m)
+}
+
+```

example/example.go

@@ -0,0 +1,14 @@
+package main
+
+import (
+	"github.com/vodkaslime/wildcard"
+)
+
+func main() {
+	matcher := wildcard.NewMatcher()
+	matcher.S = '.'
+	p := "a.c"
+	s := "abc"
+	m, _ := matcher.Match(p, s)
+	println(m)
+}