Reformat some link and fix typos

Signed-off-by: Nguyen Hai Truong <truongnh@vn.fujitsu.com>

.github/ISSUE_TEMPLATE.md

@@ -3,7 +3,7 @@
 This form is for bug reports and feature requests ONLY!
 For general questions and troubleshooting, please ask/look for answers here:
 - grpc.io mailing list: https://groups.google.com/forum/#!forum/grpc-io
-- StackOverflow, with "grpc" tag: http://stackoverflow.com/questions/tagged/grpc
+- StackOverflow, with "grpc" tag: https://stackoverflow.com/questions/tagged/grpc
 
 Issues specific to *grpc-java*, *grpc-go*, *grpc-node*, *grpc-dart*, *grpc-web* should be created in the repository they belong to (e.g. https://github.com/grpc/grpc-LANGUAGE/issues/new)
 -->
@@ -11,7 +11,7 @@ Issues specific to *grpc-java*, *grpc-go*, *grpc-node*, *grpc-dart*, *grpc-web*
 ### What version of gRPC and what language are you using?
  
  
-### What operating system (Linux, Windows, …) and version?
+### What operating system (Linux, Windows,...) and version?
  
  
 ### What runtime / compiler are you using (e.g. python version or version of gcc)
@@ -27,7 +27,7 @@ If possible, provide a recipe for reproducing the error. Try being specific and
  
 Make sure you include information that can help us debug (full error message, exception listing, stack trace, logs).
 
-See https://github.com/grpc/grpc/blob/master/TROUBLESHOOTING.md for how to diagnose problems better.
+See [TROUBLESHOOTING.md](https://github.com/grpc/grpc/blob/master/TROUBLESHOOTING.md) for how to diagnose problems better.
  
 ### Anything else we should know about your project / environment?
 

doc/interop-test-descriptions.md

@@ -652,7 +652,7 @@ The test
 downloaded from https://console.developers.google.com. Alternately, if using a
 usable auth implementation, it may specify the file location in the environment
 variable GOOGLE_APPLICATION_CREDENTIALS
-- optionally uses the flag `--oauth_scope` for the oauth scope if implementator
+- optionally uses the flag `--oauth_scope` for the oauth scope if implementer
 wishes to use service account credential instead of JWT credential. For testing
 against grpc-test.sandbox.googleapis.com, oauth scope
 "https://www.googleapis.com/auth/xapi.zoo" should be used.

src/cpp/README.md

@@ -52,7 +52,7 @@ support for crosscompiling and can be used for targeting Android platform.
 If your project is using cmake, there are several ways to add gRPC dependency.
 - install gRPC via cmake first and then locate it with `find_package(gRPC CONFIG)`. [Example](../../examples/cpp/helloworld/CMakeLists.txt)
 - via cmake's `ExternalProject_Add` using a technique called "superbuild". [Example](../../examples/cpp/helloworld/cmake_externalproject/CMakeLists.txt)
-- add gRPC source tree to your project (preferrably as a git submodule) and add it to your cmake project with `add_subdirectory`. [Example](../../examples/cpp/helloworld/CMakeLists.txt)
+- add gRPC source tree to your project (preferably as a git submodule) and add it to your cmake project with `add_subdirectory`. [Example](../../examples/cpp/helloworld/CMakeLists.txt)
 
 ## Packaging systems