Fix typos in README.md documentation

This commit corrects minor spelling errors within the README file, ensuring proper understanding of the instructions related to PHP version support and the use of PlantUML.

Author: koriym

README.md

@@ -75,7 +75,7 @@ OPTIONS
       --disable-class-name-summary describe classname without Class summary of document comment.
       --php5                     parse php source file as php5.
       --php7                     parse php source file as php7.
-      --php8                     parse php source file as php8. (not suppoted)
+      --php8                     parse php source file as php8. (not supported)
       --header='header string'   additional header string. You can specify multiple header values.
       --include='wildcard'       include target file pattern. (default: `*.php`) You can specify multiple include patterns.
       --exclude='wildcard'       exclude target file pattern. You can specify multiple exclude patterns.
@@ -152,7 +152,7 @@ $ vendor/bin/php-class-diagram test/fixtures/no-namespace
 @enduml
 ```
 
-Use PlnatUML to convert the PlantUML script to an image.
+Use PlantUML to convert the PlantUML script to an image.
 
 ![PlantUML output image.](doc/images/output.png)