Fix some typos.

Fix some typos and remove first strange characer (may be a BOM)

Author: sebuls

Language/Functions/Characters/isHexadecimalDigit.adoc

@@ -1,4 +1,4 @@
----
+---
 title: "isHexadecimalDigit()"
 categories: [ "Functions" ]
 subCategories: [ "Characters" ]
@@ -25,7 +25,7 @@ Analyse if a char is an hexadecimal digit (A-F, 0-9). Returns true if thisChar c
 === Syntax
 [source,arduino]
 ----
-`isHexadecilamDigit(thisChar)`
+`isHexadecimalDigit(thisChar)`
 ----
 
 [float]
@@ -79,4 +79,4 @@ else
 * #LANGUAGE# link:../../communication/serial/read[read()]
 
 --
-// SEE ALSO SECTION ENDS
+// SEE ALSO SECTION ENDS