[skip changelog] Document filter setting capability of Library/Boards Manager links (#1958)

Arduino IDE allows opening searches in Library Manager and Boards Manager by clicking a link with a special format in a
comment of the sketch.

During the initial implementation in Arduino IDE 1.x, support for setting the "Type" filter via the URI in addition to
specifying search keywords was attempted and claimed to work, but never did work. For this reason, it was not previously
mentioned in the sketch specification.

During the reimplementation of the Library/Boards Manager link feature for Arduino IDE 2.x, the "Type" filter setting
capability was finally truly implemented, and expanded to also support setting the "Topic" filter in Library Manager via
the same mechanism.

Now that support for the filter setting capability has been released in Arduino IDE 2.0.1, it should be documented in
the sketch specification.

Author: per1234

docs/sketch-specification.md

@@ -140,28 +140,60 @@ 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
+**(available in Arduino IDE >=1.6.9 <2.x || >=2.0.1)**
+
+A URI in a comment in the form:
+
+```text
+http://librarymanager[/TYPE_FILTER[/TOPIC_FILTER]][#SEARCH_KEYWORDS]
+```
+
+will open a search in
 [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://docs.arduino.cc/learn/starting-guide/cores) when clicked in the Arduino IDE.
+A URI in a comment in the form:
+
+```text
+http://boardsmanager[/TYPE_FILTER][#SEARCH_KEYWORDS]
+```
+
+will open a search in [Boards Manager](https://docs.arduino.cc/learn/starting-guide/cores) when clicked in the Arduino
+IDE.
+
+These links can be used to offer the user an easy way to install dependencies of the sketch.
 
-This can be used to offer the user an easy way to install dependencies of the sketch.
+The search field will be populated with the `SEARCH_KEYWORDS` fragment component of the URI. Any characters other than
+`A`-`Z`, `a`-`z`, `0`-`9`, and `:` are treated as spaces by the search algorithm, which allows multiple keywords to be
+specified via the URI.
+
+---
+
+**(available in Arduino IDE >=2.0.1)**
+
+The "**Type**" filter will be set to the optional `TYPE_FILTER` path component of the URI.
+
+The Library Manager "**Topic**" filter will be set to the optional `TOPIC_FILTER` path component of the URI.
+
+Unlike the `SEARCH_KEYWORDS` fragment, spaces and reserved characters in these components must be
+[percent-encoded](https://en.wikipedia.org/wiki/Percent-encoding) (e.g., `Signal%20Input%2FOutput`).
+
+Although the filter setting is not supported by previous IDE versions, URIs containing these path components still
+function in all other respects.
+
+---
 
 This feature is only available when using the Arduino IDE, so be sure to provide supplementary documentation to help the
 users of other development software install the sketch dependencies.
 
-This feature was added in Arduino IDE 1.6.9.
-
 ### Example
 
 ```c++
 // install the Arduino SAMD Boards platform to add support for your MKR WiFi 1010 board
-// if using the Arduino IDE, click here: http://boardsmanager#SAMD
+// if using the Arduino IDE, click here: http://boardsmanager/Arduino#SAMD
 
 // install the WiFiNINA library via Library Manager
-// if using the Arduino IDE, click here: http://librarymanager#WiFiNINA
+// if using the Arduino IDE, click here: http://librarymanager/Arduino/Communication#WiFiNINA
 #include <WiFiNINA.h>
 ```