Add Hello world tutorial

[kateinoigakukun]

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[github-actions]

Time Change: +289ms (2%)

Total Time: 10,116ms

Test name	Duration	Change
Serialization/JavaScript function call through Wasm import	26ms	+1ms (5%)	🔍
Serialization/JavaScript function call through Wasm import with int	23ms	+3ms (13%)	⚠️
Serialization/JavaScript function call from Swift	138ms	+10ms (7%)	🔍
Serialization/Swift Int to JavaScript with assignment	357ms	+25ms (6%)	🔍
Serialization/Swift Int to JavaScript with call	1,021ms	+51ms (5%)	🔍
Serialization/JavaScript Number to Swift Int	289ms	+19ms (6%)	🔍
Serialization/Swift String to JavaScript with assignment	437ms	+23ms (5%)	🔍

View Unchanged

Test name	Duration	Change
Serialization/Swift String to JavaScript with call	1,094ms	+45ms (4%)
Serialization/JavaScript String to Swift String	3,909ms	+98ms (2%)
Object heap/Increment and decrement RC	2,806ms	+13ms (0%)

View Baselines

Test name	Duration
Serialization/Call JavaScript function directly	3ms
Serialization/Assign JavaScript number directly	3ms
Serialization/Call with JavaScript number directly	3ms
Serialization/Write JavaScript string directly	3ms
Serialization/Call with JavaScript string directly	3ms