1.6.9.21 docs(man): add Es and Ps on the GR2M diagram,

Refs #88

DESCRIPTION

 Package: airGR
 Type: Package
 Title: Suite of GR Hydrological Models for Precipitation-Runoff Modelling
-Version: 1.6.9.20
+Version: 1.6.9.21
 Date: 2021-01-13
 Authors@R: c(
   person("Laurent", "Coron", role = c("aut", "trl"), comment = c(ORCID = "0000-0002-1503-6204")),

NEWS.md

@@ -2,7 +2,7 @@
 
 
 
-### 1.6.9.20 Release Notes (2021-01-13)
+### 1.6.9.21 Release Notes (2021-01-13)
 
 #### New features
 
@@ -48,6 +48,7 @@
 - `.ErrorCrit()` function now returns a warning message when a criterion computed on less than 10 time-steps (whatever the unit of the time step). ([#14](https://gitlab.irstea.fr/HYCAR-Hydro/airgr/-/issues/14))
 - Added the diagram of GR5H in the `RunModel_GR5H()` documentation. ([#49](https://gitlab.irstea.fr/HYCAR-Hydro/airgr/-/issues/49))
 - The `Exch` was renames `AExch` in the `RunModel_GR2M()` output. ([#87](https://gitlab.irstea.fr/HYCAR-Hydro/airgr/-/issues/87))
+- Added 'Es' and 'Ps' on the GR2M diagram available in the `RunModel_GR2M()` help page. ([#88](https://gitlab.irstea.fr/HYCAR-Hydro/airgr/-/issues/88))
 
 
 #### Version control and issue tracking