Readme: add usage instructions

README.md

@@ -23,6 +23,83 @@ As Maven dependency.
 
 For alternative install methods, see the [Maven Central Repo](https://search.maven.org/artifact/io.github.stscoundrel/riimut)
 
+### Usage
+
+Text to runes:
+```java
+// Ships four runic dialects under Riimut namespace.
+import io.github.stscoundrel.riimut.dialects.YoungerFuthark;
+import io.github.stscoundrel.riimut.dialects.ElderFuthark;
+import io.github.stscoundrel.riimut.dialects.MedievalFuthork;
+import io.github.stscoundrel.riimut.dialects.Futhorc;
+
+// They all implement common "Dialect" interface 
+import io.github.stscoundrel.riimut.dialects.Dialect;
+
+// From Old Groms runestone.
+String content = "auk tani karþi kristna";
+Dialect youngerFuthark = new YoungerFuthark();
+String result = YoungerFuthark.lettersToRunes(content);
+System.out.println(result); // ᛅᚢᚴ:ᛏᛅᚾᛁ:ᚴᛅᚱᚦᛁ:ᚴᚱᛁᛋᛏᚾᛅ
+
+// From 4th century axe in Jutland
+String content = "wagagastiz alu wihgu sikijaz aiþalataz";
+String elderFuthark = ElderFuthark.lettersToRunes(content);
+System.out.println(result); // ᚹᚨᚷᚨᚷᚨᛋᛏᛁᛉ:ᚨᛚᚢ:ᚹᛁᚻᚷᚢ:ᛋᛁᚲᛁᛃᚨᛉ:ᚨᛁᚦᚨᛚᚨᛏᚨᛉ
+
+// From Lord's Prayer, in Old Norse.
+String content = "Faðer uor som ast i himlüm, halgað warðe þit nama";
+String medievalFuthork = MedievalFuthork.lettersToRunes(content);
+System.out.println(result); // ᚠᛆᚦᚽᚱ:ᚢᚮᚱ:ᛋᚮᛘ:ᛆᛋᛏ:ᛁ:ᚼᛁᛘᛚᚢᛘ,:ᚼᛆᛚᚵᛆᚦ:ᚠᛆᚱᚦᚽ:ᚦᛁᛏ:ᚿᛆᛘᛆ
+
+// From 8th century Franks Casket, in late West Saxon.
+String content = "fisc.flodu.ahofonferg | enberig |";
+String futhorc = Futhorc.lettersToRunes(content);
+System.out.println(result); // ᚠᛁᛋᚳ.ᚠᛚᚩᛞᚢ.ᚪᚻᚩᚠᚩᚾᚠᛖᚱᚷ:|:ᛖᚾᛒᛖᚱᛁᚷ:|
+
+```
+
+Runes to text:
+```java
+
+// All four dialects contain runesToLetters method.
+import io.github.stscoundrel.riimut.dialects.YoungerFuthark;
+
+YoungerFuthark youngerFuthark = new YoungerFuthark();
+String runicText = "ᛅᚢᚴ:ᛏᛅᚾᛁ:ᚴᛅᚱᚦᛁ:ᚴᚱᛁᛋᛏᚾᛅ";
+String latinText = youngerFuthark.runesToLetters(runicText);
+
+System.out.println(latinText); // "auk tani karþi kristna"
+
+```
+
+Rune variants in Younger Futhark:
+
+Younger Futhark comes with long branch (Danish) and short twig (Norwegian & Swedish) variants.
+```java
+
+import io.github.stscoundrel.riimut.dialects.YoungerFuthark;
+
+String letters = "aábcdðeéfghiíjklmnoópqrstþuúvwxyýzåäæöøǫþ";
+YoungerFuthark youngerFuthark = new YoungerFuthark();
+
+// Comes with named methods per style.
+String longBranch = youngerFuthark.lettersToLongBranchRunes(letters)
+String shortTwig = youngerFuthark.lettersToShortTwigRunes(letters)
+
+System.out.println(longBranch); // ᛅᛅᛒᛋᛏᚦᛁᛁᚠᚴᚼᛁᛁᛁᚴᛚᛘᚾᚢᚢᛒᚴᚱᛋᛏᚦᚢᚢᚢᚢᛋᚢᚢᛋᚢᛅᛅᚢᚢᚢᚦ"
+System.out.println(shortTwig); // ᛆᛆᛒᛌᛐᚦᛁᛁᚠᚴᚽᛁᛁᛁᚴᛚᛘᚿᚢᚢᛒᚴᚱᛌᛐᚦᚢᚢᚢᚢᛌᚢᚢᛌᚢᛆᛆᚢᚢᚢᚦ
+
+// Instance can also be created with default style. Then lettersToRunes will use that style.
+YoungerFuthark youngerFutharkLongBranch = new YoungerFuthark(YoungerFuthark.Variant.LONG_BRANCH);
+YoungerFuthark youngerFutharkShortTwig = new YoungerFuthark(YoungerFuthark.Variant.SHORT_TWIG);
+
+// Or you can switch the style of instance at will.
+youngerFutharkLongBranch.useShortTwig();
+youngerFutharkShortTwig.useLongBranch();
+
+```
+
 #### What's in the name?
 
 "Riimut" is the Finnish word for "runes".