feat: move vec exercises into their own folder

exercises/collections/README.md

@@ -1,23 +1,11 @@
-# Collections
+# Hashmaps
+A *hash map* allows you to associate a value with a particular key.
+You may also know this by the names [*unordered map* in C++](https://en.cppreference.com/w/cpp/container/unordered_map), 
+[*dictionary* in Python](https://docs.python.org/3/tutorial/datastructures.html#dictionaries) or an *associative array* in other languages.
 
-Rust’s standard library includes a number of very useful data
-structures called collections. Most other data types represent one
-specific value, but collections can contain multiple values. Unlike
-the built-in array and tuple types, the data these collections point
-to is stored on the heap, which means the amount of data does not need
-to be known at compile time and can grow or shrink as the program
-runs.
-
-This exercise will get you familiar with two fundamental data
-structures that are used very often in Rust programs:
-
-* A *vector* allows you to store a variable number of values next to
-  each other.
-* A *hash map* allows you to associate a value with a particular key.
-  You may also know this by the names [*unordered map* in C++](https://en.cppreference.com/w/cpp/container/unordered_map), 
-  [*dictionary* in Python](https://docs.python.org/3/tutorial/datastructures.html#dictionaries) or an *associative array* in other languages.
+This is the other data structure that we've been talking about before, when
+talking about Vecs.
 
 ## Further information
 
-- [Storing Lists of Values with Vectors](https://doc.rust-lang.org/stable/book/ch08-01-vectors.html)
 - [Storing Keys with Associated Values in Hash Maps](https://doc.rust-lang.org/book/ch08-03-hash-maps.html)

exercises/vecs/README.md

@@ -0,0 +1,15 @@
+# Vectors
+
+Vectors are one of the most-used Rust data structures. In other programming
+languages, they'd simply be called Arrays, but since Rust operates on a
+bit of a lower level, an array in Rust is stored on the stack (meaning it
+can't grow or shrink, and the size needs to be known at compile time),
+and a Vector is stored in the heap (where these restrictions do not apply).
+
+Vectors are a bit of a later chapter in the book, but we think that they're
+useful enough to talk about them a bit earlier. We shall be talking about
+the other useful data structure, hash maps, later.
+
+## Further information
+
+- [Storing Lists of Values with Vectors](https://doc.rust-lang.org/stable/book/ch08-01-vectors.html)

exercises/vecs/vecs1.rs

@@ -1,8 +1,8 @@
-// vec1.rs
+// vecs1.rs
 // Your task is to create a `Vec` which holds the exact same elements
 // as in the array `a`.
 // Make me compile and pass the test!
-// Execute `rustlings hint vec1` or use the `hint` watch subcommand for a hint.
+// Execute `rustlings hint vecs1` or use the `hint` watch subcommand for a hint.
 
 // I AM NOT DONE
 

exercises/vecs/vecs2.rs

@@ -1,10 +1,10 @@
-// vec2.rs
+// vecs2.rs
 // A Vec of even numbers is given. Your task is to complete the loop
 // so that each number in the Vec is multiplied by 2.
 //
 // Make me pass the test!
 //
-// Execute `rustlings hint vec2` or use the `hint` watch subcommand for a hint.
+// Execute `rustlings hint vecs2` or use the `hint` watch subcommand for a hint.
 
 // I AM NOT DONE
 

info.toml

@@ -242,8 +242,8 @@ Now you have another tool in your toolbox!"""
 # VECS
 
 [[exercises]]
-name = "vec1"
-path = "exercises/collections/vec1.rs"
+name = "vecs1"
+path = "exercises/vecs/vecs1.rs"
 mode = "test"
 hint = """
 In Rust, there are two ways to define a Vector.
@@ -256,8 +256,8 @@ of the Rust book to learn more.
 """
 
 [[exercises]]
-name = "vec2"
-path = "exercises/collections/vec2.rs"
+name = "vecs2"
+path = "exercises/vecs/vecs2.rs"
 mode = "test"
 hint = """
 Hint 1: `i` is each element from the Vec as they are being iterated. Can you try