Fix several data names in text (COMCIFS#218)

* Replace _pd_meas.2theta_angle with _pd_meas_angle_2theta

I could not detect any traces of the _pd_meas.2theta_angle or
_pd_meas_2theta_angle data names. The closest similar name was
_pd_meas_angle_2theta. Note that the dot-separated variant
(_pd_meas.angle_2theta) was probably also never defined.

* Replace _diffrn_ambient_pressure with dot-separated name

---------

Co-authored-by: Matthew Rowles <[email protected]>

Author: vaitkus

cif_pow.dic

@@ -14,7 +14,7 @@ data_CIF_POW
     _dictionary.title             CIF_POW
     _dictionary.class             Instance
     _dictionary.version           2.5.0
-    _dictionary.date              2025-06-19
+    _dictionary.date              2025-06-20
     _dictionary.uri
 https://raw.githubusercontent.com/COMCIFS/Powder_Dictionary/master/cif_pow.dic
     _dictionary.ddl_conformance   4.2.0
@@ -4943,7 +4943,7 @@ save_pd_meas.2theta_scan
          '_pd_meas_2theta_scan'
          '_pd_meas_angle_2theta'
 
-    _definition.update            2022-10-11
+    _definition.update            2025-06-20
     _description.text
 ;
     2θ diffraction angle (in degrees) for intensity
@@ -4961,7 +4961,7 @@ save_pd_meas.2theta_scan
 
     Note that for data sets collected with constant step size,
     _pd_meas.2theta_range_* (min, max and inc) may be used
-    instead of _pd_meas.2theta_scan. _pd_meas.2theta_angle was
+    instead of _pd_meas.2theta_scan. _pd_meas_angle_2theta was
     originally a distinct but cognate definition and should not be
     used in new files.
 ;
@@ -10266,12 +10266,12 @@ save_pd_prep.pressure
 
     _definition.id                '_pd_prep.pressure'
     _alias.definition_id          '_pd_prep_pressure'
-    _definition.update            2022-10-11
+    _definition.update            2025-06-20
     _description.text
 ;
     Preparation pressure of the sample in kilopascals. This
     is particularly important for materials which are metastable
-    at the measurement pressure, _diffrn_ambient_pressure.
+    at the measurement pressure, _diffrn.ambient_pressure.
 ;
     _name.category_id             pd_prep
     _name.object_id               pressure
@@ -12870,7 +12870,7 @@ save_
 
        Deprecated _pd_refln.wavelength_id after consultation with PDDMG.
 ;
-         2.5.0                    2025-06-19
+         2.5.0                    2025-06-20
 ;
        ## Retain above version number and increment date until final
        ## release