[FL-2832] fbt: more fixes & improvements (#1854)

* github: bundling debug folder with scripts; docs: fixes & updates; fbt: added FAP_EXAMPLES variable to enable building example apps. Disabled by default. fbt: added TERM to list of proxied environment variables
* fbt: better help output; disabled implicit_deps_unchanged; added color to import validator reports
* fbt: moved debug configuration to separate tool
* fbt: proper dependency tracker for SDK source file; renamed linker script for external apps
* fbt: fixed debug elf path
* fbt: packaging sdk archive
* scripts: fixed sconsdist.py
* fbt: reworked sdk packing; docs: updates
* docs: info on cli target; linter fixes
* fbt: moved main code to scripts folder
* scripts: packing update into .tgz
* fbt, scripts: reworked copro_dist to build .tgz
* scripts: fixed naming for archived updater package
* Scripts: fix ぐるぐる回る

Co-authored-by: Aleksandr Kutuzov <alleteam@gmail.com>

scripts/fbt_tools/fbt_help.py

@@ -0,0 +1,44 @@
+targets_help = """Configuration variables:
+"""
+
+tail_help = """
+
+TASKS:
+Building:
+    firmware_all, fw_dist:
+        Build firmware; create distribution package
+    faps, fap_dist:
+        Build all FAP apps
+    fap_{APPID}, launch_app APPSRC={APPID}:
+        Build FAP app with appid={APPID}; upload & start it over USB
+
+Flashing & debugging:
+    flash, flash_blackmagic, jflash:
+        Flash firmware to target using debug probe
+    flash_usb, flash_usb_full: 
+        Install firmware using self-update package
+    debug, debug_other, blackmagic: 
+        Start GDB
+
+Other:
+    cli:
+        Open a Flipper CLI session over USB
+    firmware_cdb, updater_cdb:
+        Generate сompilation_database.json
+    lint, lint_py:
+        run linters
+    format, format_py:
+        run code formatters
+
+For more targets & info, see documentation/fbt.md
+"""
+
+
+def generate(env, **kw):
+    vars = kw["vars"]
+    basic_help = vars.GenerateHelpText(env)
+    env.Help(targets_help + basic_help + tail_help)
+
+
+def exists(env):
+    return True