Fixed several typos in markdown files. (#5005)

docs/home/contribute/style-guide.md

@@ -221,12 +221,12 @@ Typing multiple lines does **not** work. The callout style only applies to the l
 
     **Note:** This is my note. 
 
-    I didn't read the stlye guide.
+    I didn't read the style guide.
     {: .note}
 
 **Note:** This is my note. 
 
-I didn't read the stlye guide.
+I didn't read the style guide.
 {: .note}
 
 ### Ordered Lists