docs: fix capitalization in doxygen comments

Change-Id: Ibf5ee5119d12d60d382b0acef8dfd08277c18fcb
diff --git a/tools/nfdc/channel-module.hpp b/tools/nfdc/channel-module.hpp
index 6698ae8..02b01ad 100644
--- a/tools/nfdc/channel-module.hpp
+++ b/tools/nfdc/channel-module.hpp
@@ -32,7 +32,7 @@
 
 using ndn::nfd::ChannelStatus;
 
-/** \brief provides access to NFD channel dataset
+/** \brief Provides access to NFD channel dataset.
  *  \sa https://redmine.named-data.net/projects/nfd/wiki/FaceMgmt#Channel-Dataset
  */
 class ChannelModule : public Module, noncopyable
@@ -47,7 +47,7 @@
   void
   formatStatusXml(std::ostream& os) const override;
 
-  /** \brief format a single status item as XML
+  /** \brief Format a single status item as XML.
    *  \param os output stream
    *  \param item status item
    */
@@ -57,7 +57,7 @@
   void
   formatStatusText(std::ostream& os) const override;
 
-  /** \brief format a single status item as text
+  /** \brief Format a single status item as text.
    *  \param os output stream
    *  \param item status item
    */