message: docs: Fix url links in well known annotations
  URL Reader's readTree does not support default branch yet, so it has to be specified. The PR adds support for the default branch. So, this change can be reverted once the support is released.
  Created after
diff: @@ -22,7 +22,7 @@ use.
  # Example:
  metadata:
  annotations:
  - backstage.io/managed-by-location: url:http://github.com/backstage/backstage/catalog-info.yaml
  + backstage.io/managed-by-location: url:http://github.com/backstage/backstage/blob/master/catalog-info.yaml
  ```
  The value of this annotation is a so called location reference string, that
  @@ -46,7 +46,7 @@ colon is always present.
  # Example:
  metadata:
  annotations:
  - backstage.io/managed-by-origin-location: url:http://github.com/backstage/backstage/catalog-info.yaml
  + backstage.io/managed-by-origin-location: url:http://github.com/backstage/backstage/blob/master/catalog-info.yaml
  ```
  The value of this annotation is a location reference string (see above). It
  @@ -54,7 +54,7 @@ points to the location, whose registration lead to the creation of the entity.
  In most cases, the `backstage.io/managed-by-location` and
  `backstage.io/managed-by-origin-location` will be equal. They will be different
  if the original location delegates to another location. A common case is, that a
  -location is registered as `bootstrap:boostrap` which means that it is part of
  +location is registered as `bootstrap:bootstrap` which means that it is part of
  the `app-config.yaml` of a Backstage installation.
  ### backstage.io/techdocs-ref
  @@ -63,7 +63,7 @@ the `app-config.yaml` of a Backstage installation.
  # Example:
  metadata:
  annotations:
  - backstage.io/techdocs-ref: url:https://github.com/backstage/backstage.git
  + backstage.io/techdocs-ref: url:https://github.com/backstage/backstage/tree/master
  ```
  The value of this annotation is a location reference string (see above). If this
  