Some small refactorings

Author: mivano

src/Serilog.Formatting.Elasticsearch/ElasticsearchJsonFormatter.cs

@@ -135,8 +135,7 @@ protected override void WriteJsonProperty(string name, object value, ref string
         /// </summary>
         protected virtual ScalarValue DotEscapeFieldName(ScalarValue value)
         {
-            var s = value.Value as string;
-            return s != null ? new ScalarValue(DotEscapeFieldName(s)) : value;
+            return value.Value is string s ? new ScalarValue(DotEscapeFieldName(s)) : value;
         }
 
         /// <summary>

src/Serilog.Formatting.Elasticsearch/Serilog.Formatting.ElasticSearch.Symbols.nuspec

@@ -4,7 +4,7 @@
     <id>Serilog.Formatting.Elasticsearch</id>
     <version>$version$</version>
     <authors>Michiel van Oudheusden, Martijn Laarman, Mogens Heller Grabe</authors>
-    <description>The perfect way for .NET apps formatting structured log events to Elasticsearch JSON.</description>
+    <description>The perfect way for .NET apps formatting structured log events to Elasticsearch JSON. This package contains the formatter used for the Elasticsearch Sink.</description>
     <language>en-US</language>
     <projectUrl>http://serilog.net</projectUrl>
     <licenseUrl>http://www.apache.org/licenses/LICENSE-2.0</licenseUrl>

src/Serilog.Formatting.Elasticsearch/Serilog.Formatting.ElasticSearch.nuspec

@@ -4,13 +4,13 @@
     <id>Serilog.Formatting.Elasticsearch</id>
     <version>$version$</version>
     <authors>Michiel van Oudheusden, Martijn Laarman, Mogens Heller Grabe, Konstantin Erman</authors>
-    <description>The perfect way for .NET apps formatting structured log events to Elasticsearch JSON.</description>
+    <description>The perfect way for .NET apps formatting structured log events to Elasticsearch JSON. This package contains the formatter used for the Elasticsearch Sink.</description>
     <language>en-US</language>
     <projectUrl>http://serilog.net</projectUrl>
     <licenseUrl>http://www.apache.org/licenses/LICENSE-2.0</licenseUrl>
     <iconUrl>http://serilog.net/images/serilog-sink-nuget.png</iconUrl>
     <repository type="git" url="https://github.com/serilog/serilog-sinks-elasticsearch" />
-    <tags>serilog logging elasticsearch</tags>
+    <tags>serilog logging elasticsearch formatters</tags>
     <dependencies>
       <dependency id="Serilog" version="2.6.0" />
       <dependency id="Elasticsearch.Net" version="6.0.0" />