DOCSP-26681 PHP library version update (#847)

* update php library/extension compat tables

* fix footnotes

* fix footnotes

* fix footnote numbering

* fix footnote numbering

* brevity in footnote

Author: ajhuh-mdb

source/includes/language-compatibility-table-php.rst

@@ -14,6 +14,16 @@
      - PHP 5.6
      - PHP 5.5
 
+   * - ext 1.15 + lib 1.15 [#PHP1.15-version-parity]_
+     - ✓
+     - ✓
+     - ✓
+     - ✓
+     - ✓
+     -
+     -
+     -
+     -
    * - ext 1.14 + lib 1.13
      - ✓
      - ✓
@@ -144,3 +154,4 @@
      - ✓
      - ✓
      - ✓
+

source/includes/mongodb-compatibility-table-php.rst

@@ -16,6 +16,18 @@
      - MongoDB 3.2
      - MongoDB 3.0
      - MongoDB 2.6
+  
+   * - ext 1.15 + lib 1.15 [#PHP1.15-version-parity]_
+     - ✓
+     - ✓
+     - ✓
+     - ✓
+     - ✓
+     - ✓
+     -
+     -
+     -
+     -
    * - ext 1.14 + lib 1.13
      - ✓
      - ✓
@@ -182,6 +194,9 @@
      - ✓
      - ✓
 
+.. [#PHP1.15-version-parity] Version 1.14 of the MongoDB PHP library has been 
+   skipped to restore version parity between the library and extension.
+
 .. [#PHPC1.10-PHPLIB1.9-driver-support] The extension 1.10 + library 1.9
    driver does not support snapshot reads on secondaries. For more
    information, see the