update dead documentation links (#1690)

* update documentation links

* Update docs/library-specification.md

Co-authored-by: per1234 <accounts@perglass.com>

Co-authored-by: per1234 <accounts@perglass.com>

Author: umbynos

docs/library-specification.md

@@ -8,7 +8,7 @@ This is the specification for the Arduino library format, to be used with Arduin
 This new library format is intended to be used in tandem with **Library Manager**, available since Arduino IDE 1.6.2.
 The Library Manager allows users to automatically download and install libraries needed in their projects, with an easy
 to use graphical interface in the
-[Arduino IDE](https://www.arduino.cc/en/guide/libraries#toc3)/[Arduino IDE 2.0](https://www.arduino.cc/en/Tutorial/getting-started-with-ide-v2/ide-v2-installing-a-library#installing-a-library)
+[Arduino IDE](https://docs.arduino.cc/software/ide-v1/tutorials/installing-libraries#using-the-library-manager)/[Arduino IDE 2.0](https://docs.arduino.cc/software/ide-v2/tutorials/ide-v2-installing-a-library#installing-a-library)
 and
 [Arduino Web Editor](https://create.arduino.cc/projecthub/Arduino_Genuino/getting-started-with-arduino-web-editor-on-various-platforms-4b3e4a#toc-libraries-and-the-arduino-web-editor-11)
 as well as [`arduino-cli lib`](commands/arduino-cli_lib.md).

docs/package_index_json-specification.md

@@ -3,7 +3,7 @@ provide Boards Manager installation support for a platform, a JSON formatted ind
 specification for that file.
 
 Boards Manager functionality is provided by [Arduino CLI](getting-started.md#adding-3rd-party-cores),
-[Arduino IDE](https://www.arduino.cc/en/Guide/Cores), and Arduino Pro IDE.
+[Arduino IDE](https://docs.arduino.cc/learn/starting-guide/cores), and Arduino Pro IDE.
 
 ## Naming of the JSON index file
 

docs/sketch-specification.md

@@ -130,10 +130,11 @@ no requirement to store sketches in the sketchbook folder.
 ## Library/Boards Manager links
 
 A URI in a comment in the form `http://librarymanager#SEARCH_TERM` will open a search for SEARCH_TERM in
-[Library Manager](https://www.arduino.cc/en/guide/libraries#toc3) when clicked in the Arduino IDE.
+[Library Manager](https://docs.arduino.cc/software/ide-v1/tutorials/installing-libraries#using-the-library-manager) when
+clicked in the Arduino IDE.
 
 A URI in a comment in the form `http://boardsmanager#SEARCH_TERM` will open a search for SEARCH_TERM in
-[Boards Manager](https://www.arduino.cc/en/Guide/Cores) when clicked in the Arduino IDE.
+[Boards Manager](https://docs.arduino.cc/learn/starting-guide/cores) when clicked in the Arduino IDE.
 
 This can be used to offer the user an easy way to install dependencies of the sketch.