Update docs

Author: petk

docs/cmake/cmake-code-style.md

@@ -92,10 +92,12 @@ On the contrary, variable names are case-sensitive.
   a backslash character (`\`) followed by a new line:
 
   ```cmake
-  message("\
+  message(STATUS "\
   This string is concatenated \
   to a single line.\
   ")
+
+  # Output: This string is concatenated to a single line.
   ```
 
 * When defining path variables, exclude the trailing directory delimiter (`/`).

docs/cmake/introduction.md

@@ -192,7 +192,7 @@ brackets `{}`.
 
 ```cmake
 set(foobar "value")
-message(STATUS ${foobar})
+message(STATUS "${foobar}")
 
 # Output: value
 ```
@@ -272,13 +272,22 @@ etc.) and passed as-is. No escaping of special characters is needed, but also
 variables are not expanded. They are most commonly used for passing strings of
 code or regular expressions.
 
+For example
+
 ```cmake
-message([=[
+message(STATUS [=[
 Inside bracket arguments the \-escape sequences and ${variable} references are
 not evaluated. Argument can also contain ; and other special ]] characters.
 ]=])
 ```
 
+will output:
+
+```
+Inside bracket arguments the \-escape sequences and ${variable} references are
+not evaluated. Argument can also contain ; and other special ]] characters.
+```
+
 ## 5. Targets
 
 CMake revolves around targets, which represent various components of the