Fix lots of spelling errors (#7751)

* Fix a typo

* Fix lots of spelling errors

* Fix a few more spelling mistakes

* s/parsable/parseable/

* Don't touch the third party files

* Cloneable is the preferred C# term

* Copyable is the preferred C++ term

* Revert "s/parsable/parseable/"

This reverts commit 534ecf7675222f39d98928c7e1489b56b004b774.

* Revert unparseable->unparsable corrections
diff --git a/java/README.md b/java/README.md
index 2e2f952..dea9e76 100644
--- a/java/README.md
+++ b/java/README.md
@@ -68,7 +68,7 @@
 
 Most users should follow the instructions above to use protobuf Java runtime.
 If you are contributing code to protobuf or want to use a protobuf version
-that hasn't been officially released yet, you can folllow the instructions
+that hasn't been officially released yet, you can follow the instructions
 below to build protobuf from source code.
 
 ### Build from Source - With Maven