Update CONTRIBUTING.md - small typo fix (#100)

Signed-off-by: Nikolaos Dymitriadis <nikolaos.dymitriadis@iohk.io>

CONTRIBUTING.md

@@ -221,7 +221,7 @@ The `<type>` and `<summary>` fields are mandatory, the `(<scope>)` field is opti
 
 ##### Type
 
-Must classify commit to the certain type. Some of he examples of good types to use:
+Must classify commit to the certain type. Some of the examples of good types to use:
 
 * **build**: Changes that affect the build system or external dependencies
 * **ci**: Changes to our CI configuration files and scripts
@@ -299,4 +299,4 @@ If the commit reverts a previous commit, it should begin with `revert: `, follow
 The content of the commit message body should contain:
 
 - information about the SHA of the commit being reverted in the following format: `This reverts commit <SHA>`,
-- a clear description of the reason for reverting the commit message.
+- a clear description of the reason for reverting the commit message.