[7.x][DOCS] Makes minor changes in section titles and fixes version numbers in Installation. (#1058)

Author: szabosteve

docs/installation.asciidoc

@@ -23,13 +23,13 @@ command:
 
 [source,sh]
 ------------------------------------
-gem install elasticsearch -v 6.0.0
+gem install elasticsearch -v 7.0.0
 ------------------------------------
 
 
 Or you can add a specific version of {es} to your Gemfile:
 
 [source,ruby]
 ------------------------------------
-gem 'elasticsearch', '~> 6.0'
+gem 'elasticsearch', '~> 7.0'
 ------------------------------------

docs/model.asciidoc

@@ -8,7 +8,7 @@ It uses the `elasticsearch` Rubygem as the client communicating with the Elastic
 
 
 [discrete]
-=== Features at a Glance
+=== Features
 
 * ActiveModel integration with adapters for ActiveRecord and Mongoid
 * Enumerable-based wrapper for search results

docs/overview.asciidoc

@@ -47,7 +47,7 @@ client.search index: 'my-index', body: { query: { match: { title: 'test' } } }
 
 
 [discrete]
-=== Features at a Glance
+=== Features
 
 * Pluggable logging and tracing
 * Pluggable connection selection strategies (round-robin, random, custom)

docs/persistence.asciidoc

@@ -14,7 +14,7 @@ The `Elasticsearch::Persistence::Repository` module provides an implementation o
 
 
 [discrete]
-==== Features At a Glance
+==== Features
 
 * Access to the Elasticsearch client
 * Setting the index name, document type, and object class for deserialization

docs/rails.asciidoc

@@ -6,7 +6,7 @@ provides features suitable for Ruby on Rails applications.
 
 
 [discrete]
-=== Features at a Glance
+=== Features
 
 * Rake tasks for importing data from application models
 * Integration with Rails' instrumentation framework