config_parser: Allow modifying Parser map

This makes it possible to mutate the map owned by the parser. This will
eventually be used for implementing write updates.

Change-Id: I89deb4073a0a3bd59528c6b70fc55b49bc6cd944
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/src/config_parser.hpp b/src/config_parser.hpp
index 6b633e9..8ec693a 100644
--- a/src/config_parser.hpp
+++ b/src/config_parser.hpp
@@ -160,6 +160,8 @@
 class Parser
 {
   public:
+    SectionMap map;
+
     Parser() = default;
 
     /** @brief Constructor
@@ -167,12 +169,6 @@
      */
     Parser(const fs::path& filename);
 
-    /** @brief Retrieve the map of all values in the file */
-    inline const SectionMap& getMap() const noexcept
-    {
-        return sections;
-    }
-
     /** @brief Determine if there were warnings parsing the file
      *  @return The number of parsing issues in the file
      */
@@ -196,7 +192,6 @@
 
   private:
     fs::path filename;
-    SectionMap sections;
     std::vector<std::string> warnings;
 };