[v3] Markdown sub-headings must be parent level incremented by one.

ErikSchierboom · mirkoperillo · commit 52d574b57742 · 2021-02-12T20:10:54.000+01:00
The full specification can be found [here](https://github.com/exercism/docs/blob/main/contributing/standards/markdown.md).
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
@@ -149,10 +149,10 @@ Each problem/submodule has three source sets:
 ### Prerequisites
 Before you proceed, please ensure that you have `jq` (library that parses JSON) & `ruby` installed on your machine.
 
-##### Debian Linux
+#### Debian Linux
 `sudo apt-get install jq ruby-full`
 
-##### macOS
+#### macOS
 `brew install jq ruby`
 
 If you are going to make significant contribution(s) to the track, you might find it handy to have a complete local install of exercism on your computer.  This way, you can run the full suite of tests without having to create/update a PR.
diff --git a/exercises/concept/chars/.docs/hints.md b/exercises/concept/chars/.docs/hints.md
@@ -1,6 +1,6 @@
 # Hints
 
-### 1. Replace any spaces encountered with underscores
+## 1. Replace any spaces encountered with underscores
 
 - [This tutorial][chars-tutorial] is useful.
 - [Reference documentation][chars-docs] for `char`s is here.
@@ -9,15 +9,15 @@
 - See [this method][iswhitespace] for detecting spaces. Remember it is a static method.
 - `char` literals are enclosed in single quotes.
 
-### 2. Replace control characters with the upper case string "CTRL"
+## 2. Replace control characters with the upper case string "CTRL"
 
 - See [this method][iscontrol] to check if a character is a control character.
 
-### 3. Convert kebab-case to camel-case
+## 3. Convert kebab-case to camel-case
 
 - See [this method][toupper] to convert a character to upper case.
 
-### 4. Omit Greek lower case letters
+## 4. Omit Greek lower case letters
 
 - `char`s support the default equality and comparison operators.
 
diff --git a/exercises/concept/chars/.docs/instructions.md b/exercises/concept/chars/.docs/instructions.md
@@ -8,7 +8,7 @@ zero or more letters and underscores.
 
 In all cases the input string is guaranteed to be non-null. Note that the `clean` method should treat an empty string as valid.
 
-### 1. Replace any spaces encountered with underscores
+## 1. Replace any spaces encountered with underscores
 
 Implement the (_static_) `Identifier.clean()` method to replace any spaces with underscores. This also applies to leading and trailing spaces.
 
@@ -17,7 +17,7 @@ Identifier.clean("my   Id");
 // => "my___Id"
 ```
 
-### 2. Replace control characters with the upper case string "CTRL"
+## 2. Replace control characters with the upper case string "CTRL"
 
 Modify the (_static_) `Identifier.clean()` method to replace control characters with the upper case string `"CTRL"`.
 
@@ -26,7 +26,7 @@ Identifier.clean("my\0Id");
 // => "myCTRLId",
 ```
 
-### 3. Convert kebab-case to camelCase
+## 3. Convert kebab-case to camelCase
 
 Modify the (_static_) `Identifier.clean()` method to convert kebab-case to camelCase.
 
@@ -35,7 +35,7 @@ Identifier.Clean("à-ḃç");
 // => "àḂç"
 ```
 
-### 4. Omit Greek lower case letters
+## 4. Omit Greek lower case letters
 
 Modify the (_static_) `Identifier.clean()` method to omit any Greek letters in the range 'α' to 'ω'.
 
diff --git a/exercises/concept/switch-statement/.docs/hints.md b/exercises/concept/switch-statement/.docs/hints.md
@@ -2,11 +2,11 @@
 
 - The [`switch` statement documentation][switch-statement] provides an introduction to `switch` statements.
 
-### 1. Output descriptions of the players based on their shirt number
+## 1. Output descriptions of the players based on their shirt number
 
 - The [`break`][break] statement is useful here.
 
-### 2. Raise an alert if an unknown shirt number is encountered
+## 2. Raise an alert if an unknown shirt number is encountered
 
 - The [`default`][default] statement can be used here.
 
diff --git a/exercises/concept/switch-statement/.docs/instructions.md b/exercises/concept/switch-statement/.docs/instructions.md
@@ -2,7 +2,7 @@
 
 You are developing a system to help the staff of a football/soccer club's web site report on matches. Data is received from a variety of sources and piped into a single stream after being cleaned up.
 
-### 1. Output descriptions of the players based on their shirt number
+## 1. Output descriptions of the players based on their shirt number
 
 The team only ever plays a 4-3-3 formation and has never agreed with the 1965 change to the rules allowing for substitutions, never mind enlarged squads.
 
@@ -26,7 +26,7 @@ PlayAnalyzer.onField(10);
 // => "striker"
 ```
 
-### 2. Raise an alert if an unknown shirt number is encountered
+## 2. Raise an alert if an unknown shirt number is encountered
 
 Modify the `PlayAnalyzer.onField()` method to throw an `IllegalArgumentException` when a shirt number outside the range 1-11 is processed.
 
