Updated README to remove mention of .bbx for bibliographies.

README

@@ -417,7 +417,7 @@ Options
 :   Specify bibliography database to be used in resolving
     citations. The database type will be determined from the
     extension of *FILE*, which may be `.mods` (MODS format),
-    `.bib` (BibTeX format), `.bbx` (BibLaTeX format),
+    `.bib` (BibTeX/BibLaTeX format),
     `.ris` (RIS format), `.enl` (EndNote format),
     `.xml` (EndNote XML format), `.wos` (ISI format),
     `.medline` (MEDLINE format), `.copac` (Copac format),
@@ -1811,18 +1811,17 @@ Pandoc can automatically generate citations and a bibliography in a number of
 styles (using Andrea Rossato's `hs-citeproc`). In order to use this feature,
 you will need a bibliographic database in one of the following formats:
 
-  Format          File extension
-  ------------    --------------
-  MODS            .mods
-  BibTeX          .bib
-  BibLaTeX        .bbx
-  RIS             .ris
-  EndNote         .enl
-  EndNote XML     .xml
-  ISI             .wos
-  MEDLINE         .medline
-  Copac           .copac
-  JSON citeproc   .json
+  Format            File extension
+  ------------      --------------
+  MODS              .mods
+  BibTeX/BibLaTeX   .bib
+  RIS               .ris
+  EndNote           .enl
+  EndNote XML       .xml
+  ISI               .wos
+  MEDLINE           .medline
+  Copac             .copac
+  JSON citeproc     .json
 
 You will need to specify the bibliography file using the `--bibliography`
 command-line option (which may be repeated if you have several