feat(challenges): add valid-parentheses

challenges/valid-parentheses/test/1/input.txt

@@ -0,0 +1 @@
+()

challenges/valid-parentheses/test/1/output.txt

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+true

challenges/valid-parentheses/test/2/input.txt

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+()[]{}

challenges/valid-parentheses/test/2/output.txt

@@ -0,0 +1 @@
+true

challenges/valid-parentheses/test/3/input.txt

@@ -0,0 +1 @@
+(]

challenges/valid-parentheses/test/3/output.txt

@@ -0,0 +1 @@
+false

challenges/valid-parentheses/test/4/input.txt

@@ -0,0 +1 @@
+([])

challenges/valid-parentheses/test/4/output.txt

@@ -0,0 +1 @@
+true

challenges/valid-parentheses/test/5/input.txt

@@ -0,0 +1 @@
+(abc[def])

challenges/valid-parentheses/test/5/output.txt

@@ -0,0 +1 @@
+true