Minor clarifications in grammar and docs.

Signed-off-by: Łukasz Dywicki <luke@code-house.org>

Author: splatch

bundles/org.connectorio.bittpl/README.adoc

@@ -8,32 +8,34 @@ Templates can be constructed from four elements described in table below.
 
 [cols="1,2,1,1"]
 |===
-|Name | Pattern| Size (bit count)| Notes
+|Name | Pattern| Size (bit count)| Sample expr.
 
 | Nibble
 | `'0' .. '9' \| 'a' .. 'f' \| 'A' .. 'F'`
 | 4
-|
+| `xAA`
 
 | Nibble variable
 | `*`
 | 4
-| Written as `0000b`
+| `xA*`
 
 | Bit
 | `'0' .. '9' \| 'a' .. 'f' \| 'A' .. 'F'`
 | 1
-|
+| `b0010`
 
 | Bit variable
 | `.`
 | 1
-| Written as `0b`.
+| `b1.0.`
 
 |===
 
-When template is turned again into message its variable part always default to `0b`.
-It is duty of caller to fill placeholders with proper values.
+The template can be also used to create messages.
+
+When template is turned into message, variable part is defaulted to `0x00`.
+Caller have to fill placeholders with proper values.
 What is notable - writing does not have to follow variable parts.
 
 === Example templates

bundles/org.connectorio.bittpl/src/main/antlr4/org/connectorio/bittpl/parser/BitTPL.g4

@@ -17,7 +17,8 @@
  */
 grammar BitTPL;
 
-// This grammar is a basic definition of permitted inputs for bit templates
+// This grammar is a basic definition of permitted inputs for byte based messages.
+// It allows to define a selective templates and matching patterns.
 
 segments
     : segment* EOF
@@ -36,16 +37,18 @@ octet
     ;
 
 
-hexSeq : HEX_SQ+;
-bitSeq : BIT_SQ+;
+hexSeq : HEX_SEQ+;
+bitSeq : BIT_SEQ+;
 
-BIT_SQ : BIT | '.';
+BIT_SEQ : BIT | BIT_ANY;
+BIT_ANY : '.';
 BIT
     : '0'
     | '1'
     ;
 
-HEX_SQ : HEX_DIGIT | '*';
+HEX_SEQ : HEX_DIGIT | HEX_ANY;
+HEX_ANY : '*';
 HEX_DIGIT
     : '0' .. '9'
     | 'a' .. 'f'