started writing lexer after making string lib

string/docs/find/find.md

@@ -0,0 +1,21 @@
+# string_Find
+Look for the first occurence of `needle` in `haystack` and return its index in the string. If it isn't found, return -1.
+
+## Arguments
+- haystack (string): the string to search.
+- needle (string): the substring to look for.
+
+## Returns
+index (int): the index of the first occurence of `needle` in `haystack`. If it isn't found, return -1.
+
+## Example
+### Ground
+```python
+call !string_Find "abcdefg" "d" &index
+println $index # 3
+```
+
+### Solstice
+```c
+puts string_Find("abcdefg", "d") // 3
+```