chore: Update gem version in documentation to 0.10 (#103)

Author: dazuma

README.md

@@ -60,7 +60,7 @@ Create a `Gemfile` listing the Functions Framework as a dependency:
 ```ruby
 # Gemfile
 source "https://rubygems.org"
-gem "functions_framework", "~> 0.9"
+gem "functions_framework", "~> 0.10"
 ```
 
 Create a file called `app.rb` and include the following code. This defines a

docs/overview.md

@@ -64,7 +64,7 @@ Create a `Gemfile` listing the Functions Framework as a dependency:
 ```ruby
 # Gemfile
 source "https://rubygems.org"
-gem "functions_framework", "~> 0.9"
+gem "functions_framework", "~> 0.10"
 ```
 
 Create a file called `app.rb` and include the following code. This defines a

docs/writing-functions.md

@@ -111,7 +111,7 @@ dependency on Sinatra in your `Gemfile`:
 
 ```ruby
 source "https://rubygems.org"
-gem "functions_framework", "~> 0.9"
+gem "functions_framework", "~> 0.10"
 gem "sinatra", "~> 2.0"
 ```
 
@@ -470,7 +470,7 @@ Following is a typical layout for a Functions Framework based project.
 ```ruby
 # Gemfile
 source "https://rubygems.org"
-gem "functions_framework", "~> 0.9"
+gem "functions_framework", "~> 0.10"
 ```
 
 ```ruby