note about latest details being on master branch

[ci skip]

doc/update/2.6-to-3.0.md

 # From 2.6 to 3.0
+*Make sure you view this [upgrade guide from the `master` branch](../../../master/doc/update/2.6-to-3.0.md) for the most up to date instructions.*
 ## 1. Stop server & resque

doc/update/2.9-to-3.0.md

 # From 2.9 to 3.0
+*Make sure you view this [upgrade guide from the `master` branch](../../../master/doc/update/2.9-to-3.0.md) for the most up to date instructions.*
 ## 1. Stop server & resque

doc/update/3.0-to-3.1.md

 # From 3.0 to 3.1
+*Make sure you view this [upgrade guide from the `master` branch](../../../master/doc/update/3.0-to-3.1.md) for the most up to date instructions.*
 **IMPORTANT!**

doc/update/3.1-to-4.0.md

 # From 3.1 to 4.0
+*Make sure you view this [upgrade guide from the `master` branch](../../../master/doc/update/3.1-to-4.0.md) for the most up to date instructions.*
 ## Important changes

doc/update/4.0-to-4.1.md

 # From 4.0 to 4.1
+*Make sure you view this [upgrade guide from the `master` branch](../../../master/doc/update/4.0-to-4.1.md) for the most up to date instructions.*
 ## Important changes

doc/update/4.1-to-4.2.md

 # From 4.1 to 4.2
+*Make sure you view this [upgrade guide from the `master` branch](../../../master/doc/update/4.1-to-4.2.md) for the most up to date instructions.*
 ## 1. Stop server & Resque

doc/update/4.2-to-5.0.md

 # From 4.2 to 5.0
+*Make sure you view this [upgrade guide from the `master` branch](../../../master/doc/update/4.2-to-5.0.md) for the most up to date instructions.*
 ## Warning

doc/update/5.0-to-5.1.md

 # From 5.0 to 5.1
+*Make sure you view this [upgrade guide from the `master` branch](../../../master/doc/update/5.0-to-5.1.md) for the most up to date instructions.*
 ## Warning

doc/update/5.1-to-5.2.md

 # From 5.1 to 5.2
+*Make sure you view this [upgrade guide from the `master` branch](../../../master/doc/update/5.1-to-5.2.md) for the most up to date instructions.*
 ## Warning

doc/update/5.1-to-5.4.md

 # From 5.1 to 5.4
+*Make sure you view this [upgrade guide from the `master` branch](../../../master/doc/update/5.1-to-5.4.md) for the most up to date instructions.*
 Also works starting from 5.2.

doc/update/5.1-to-6.0.md

 # From 5.1 to 6.0
+*Make sure you view this [upgrade guide from the `master` branch](../../../master/doc/update/5.1-to-6.0.md) for the most up to date instructions.*
 ## Warning

doc/update/5.2-to-5.3.md

 # From 5.2 to 5.3
+*Make sure you view this [upgrade guide from the `master` branch](../../../master/doc/update/5.2-to-5.3.md) for the most up to date instructions.*
 ## Warning

doc/update/5.3-to-5.4.md

 # From 5.3 to 5.4
+*Make sure you view this [upgrade guide from the `master` branch](../../../master/doc/update/5.3-to-5.4.md) for the most up to date instructions.*
 ## 0. Backup

doc/update/5.4-to-6.0.md

 # From 5.4 to 6.0
+*Make sure you view this [upgrade guide from the `master` branch](../../../master/doc/update/5.4-to-6.0.md) for the most up to date instructions.*
 ## Warning

doc/update/6.0-to-6.1.md

 # From 6.0 to 6.1
+*Make sure you view this [upgrade guide from the `master` branch](../../../master/doc/update/6.0-to-6.1.md) for the most up to date instructions.*
 ## Warning

doc/update/6.1-to-6.2.md

 # From 6.1 to 6.2
+*Make sure you view this [upgrade guide from the `master` branch](../../../master/doc/update/6.1-to-6.2.md) for the most up to date instructions.*
 **You should update to 6.1 before installing 6.2 so all the necessary conversions are run.**

doc/update/6.2-to-6.3.md

 # From 6.2 to 6.3
+*Make sure you view this [upgrade guide from the `master` branch](../../../master/doc/update/6.2-to-6.3.md) for the most up to date instructions.*
 **Requires version: 6.1 or 6.2.**

doc/update/6.3-to-6.4.md

 # From 6.3 to 6.4
+*Make sure you view this [upgrade guide from the `master` branch](../../../master/doc/update/6.3-to-6.4.md) for the most up to date instructions.*
 ## 0. Backup

doc/update/6.4-to-6.5.md

 # From 6.4 to 6.5
+*Make sure you view this [upgrade guide from the `master` branch](../../../master/doc/update/6.4-to-6.5.md) for the most up to date instructions.*
 ## 0. Backup

doc/update/6.5-to-6.6.md

 # From 6.5 to 6.6
+*Make sure you view this [upgrade guide from the `master` branch](../../../master/doc/update/6.5-to-6.6.md) for the most up to date instructions.*
 ## 0. Backup