Fix Module Title and other comments that are incorrect

1. +++ b/README.txt
   @@ -13,7 +13,7 @@ CONTENTS
   -Drupal 8 RdfUI module provides User Interfaces for site builders to integrate
   +Drupal 8 RDF UI module provides User Interfaces for site builders to integrate
   

   *The* Drupal 8 RDF UI module....

2. +++ b/rdf_builder/README.txt
   @@ -15,7 +15,7 @@ CONTENTS
   -Drupal 8 RdfUI module provides User Interfaces for site builders to choose types
   +Drupal 8 RDF UI module provides User Interfaces for site builders to choose types
   

   same.

3. +++ b/rdf_builder/README.txt
   @@ -15,7 +15,7 @@ CONTENTS
    and properties from schema.org, and the content structure will be automatically
    built on Drupal, and include the schema.org out of the box.
   

   include the schema.org *mappings* out of the box.

4. +++ b/rdf_builder/src/Tests/ContentTypeBuilderTest.php
   @@ -12,7 +12,7 @@ use Drupal\simpletest\WebTestBase;
   - * @group Rdf Builder
   + * @group RDF Builder
   

   RDF UI Builder

5. +++ b/src/Form/FieldMappings.php
   @@ -103,7 +103,7 @@ class FieldMappings extends OverviewBase {
   -        $this->t('Rdf Predicate'),
   +        $this->t('RDF Predicate'),
   

   Let's standardize on RDF property

6. +++ b/src/Tests/RdfUiContentMappingTest.php
   @@ -29,9 +29,9 @@ class RdfUiContentMappingTest extends NodeTestBase {
   +      'name' => 'RDF UI Content Mapping',
   +      'description' => 'Ensures that RDF mappings for Content type works correctly.',
   +      'group' => 'RDF UI',
   

   Ensures that *the* RDF mappings for *a* Content Type work correctly.

7. +++ b/src/Tests/RdfUiFieldMappingTest.php
   @@ -61,7 +61,7 @@ class RdfUiFieldMappingTest extends FieldUiTestBase {
   +    // Add RDF predicate and save.
   

   property

8. +++ b/src/Tests/RdfUiFieldMappingTest.php
   @@ -99,7 +99,7 @@ class RdfUiFieldMappingTest extends FieldUiTestBase {
   +    // Add RDF predicate and save.
   

   property

Good initiative and nice improvements. Thanks Sachini!