docs: update API documenation to reflect recent changes

Signed-off-by:  Eric Callahan <arksine.code@gmail.com>

README.md

@@ -21,4 +21,4 @@ Users:\
 [user_changes.md](/docs/user_changes.md) - March 10th 2021
 
 Developers:\
-[api_changes.md](/docs/api_changes.md) - January 31st 2021
+[api_changes.md](/docs/api_changes.md) - March 15th 2021

docs/api_changes.md

@@ -1,5 +1,12 @@
 This document keeps a record of all changes to Moonraker's web APIs.
 
+### March 15th 2021
+- The `data` field for gcode thumbnails is now deprecated and will
+  be removed in the near future.  Thumbnails are now saved to png
+  files in a `thumbs` directory relative to a gcode file's location.
+  This path is available in the `relative_path` field for each
+  thumbnail entry in the metadata.
+
 ### January 31st 2021
 - The `GET /server/temperature_store` endpoint now only returns fields
   that each sensor reports.  For example, if a particuarly temperature

docs/web_api.md

@@ -722,7 +722,7 @@ path relative to the specified "root".  Note that if the query st
         width: <in_pixels>,
         height: <in_pixels>,
         size: <length_of_string>,
-        data: <base64_string>
+        relative_path: <relative_path_to_png>
       }, ...
     ]
   }
@@ -1183,6 +1183,7 @@ In these cases the current status will be returned immediately.
   {
       'version_info': {
           'moonraker': {
+              owner: <string>,
               branch: <string>,
               remote_alias: <string>,
               version: <string>,
@@ -1192,9 +1193,20 @@ In these cases the current status will be returned immediately.
               is_valid: <bool>,
               is_dirty: <bool>,
               detached: <bool>,
-              debug_enabled: <bool>
+              debug_enabled: <bool>,
+              commits_behind: [
+                  {
+                      author: <string>,
+                      date: <unix_time>,
+                      subject: <string>,
+                      message: <string>,
+                      sha: <string>,
+                      tag: <string or null>
+                  },...
+              ]
           },
           'klipper': {
+              owner: <string>,
               branch: <string>,
               remote_alias: <string>,
               version: <string>,
@@ -1204,7 +1216,8 @@ In these cases the current status will be returned immediately.
               is_valid: <bool>,
               is_dirty: <bool>,
               detached: <bool>,
-              debug_enabled: <bool>
+              debug_enabled: <bool>,
+              commits_behind: []
           },
           'client_name_1': {
               name: <string>,
@@ -1627,6 +1640,7 @@ The APIs below are avilable when the `[history]` plugin has been configured.
       jobs: [
         {
             "job_id": <unique job id>,
+            "exists": <boolean>,
             "end_time": <end_time>,
             "filament_used": <filament_used>,
             "filename": <filename>,
@@ -1655,6 +1669,7 @@ The APIs below are avilable when the `[history]` plugin has been configured.
   {
       "job": {
         "job_id": <unique job id>,
+        "exists": <boolean>,
         "end_time": <end_time>,
         "filament_used": <filament_used>,
         "filename": <filename>,