feat: flip swap mechanism — MD as primary, RST as override (Phase 1)

This is the first of three phases inverting the per-page swap mechanism
so MD becomes the canonical primary and RST becomes the rare override.

Phase 1 — file renames + conf.py exclude_patterns flip only:
- Rename docs/**/md-<stem>.md to docs/**/<stem>.md (drop md- prefix)
  for all 254 stems previously listed in docs/_swap.txt
- Rename docs/**/<stem>.rst to docs/**/rst-<stem>.rst (add rst- prefix)
  for the same 254 stems
- Repurpose docs/_swap.txt as docs/_rst_overrides.txt; initially empty
  comment-only since no pages need the RST fallback right now
- conf.py exclude_patterns flipped: rst-*.rst is now excluded by default
  instead of md-*.md
- conf.py runtime-artifact references updated to _rst_override_state.json
  and _md_exclude.txt (Phase 2 will rewrite swap_sources.py to produce
  these names; for now no swap script runs because overrides list is empty)

Phase 2 (next commit on this branch) will rewrite scripts/swap_sources.py
with inverted rename direction, delete scripts/import_myst.py + tests, and
update tests/test_swap_sources.py for the new semantics.

Phase 3 will be the cleanup pass and ready-for-review flip.

Generated by robots https://vyos.io

1 files changed, 40 insertions, 0 deletions

diff --git a/docs/configuration/system/default-route.md b/docs/configuration/system/default-route.md
new file mode 100644
index 00000000..9f2793d1
--- /dev/null
+++ b/docs/configuration/system/default-route.md
@@ -0,0 +1,40 @@
+(default-gateway)=
+
+# Default Gateway/Route
+
+In the past (VyOS 1.1) used a gateway-address configured under the system tree
+({cfgcmd}`set system gateway-address <address>`), this is no longer supported
+and existing configurations are migrated to the new CLI command.
+
+## Configuration
+
+```{cfgcmd} set protocols static route 0.0.0.0/0 next-hop \<address\>
+
+Specify static route into the routing table sending all non local traffic
+to the nexthop address \<address\>.
+```
+
+```{cfgcmd} delete protocols static route 0.0.0.0/0
+
+Delete default route from the system.
+```
+
+
+## Operation
+
+```{opcmd} show ip route 0.0.0.0
+
+Show routing table entry for the default route.
+
+:::{code-block} none
+vyos@vyos:~$ show ip route 0.0.0.0
+Routing entry for 0.0.0.0/0
+Known via "static", distance 10, metric 0, best
+Last update 09:46:30 ago
+* 172.18.201.254, via eth0.201
+:::
+```
+
+:::{seealso}
+Configuration of {ref}`routing-static`
+:::